Merge pull request #1355 from bryanthaboi/dev

Co-authored-by: Cursor <cursoragent@cursor.com>

CONTRIBUTING-mods.md

@@ -271,7 +271,7 @@ What has no stand-in, because there is nothing honest to reroute it to:
 
 | Still refused | Why |
 | --- | --- |
-| `love.thread` | a LÖVE thread is a fresh Lua state with the full standard library, which no environment-based sandbox in this state can reach |
+| `love.thread` | a LÖVE thread is a fresh Lua state with the full standard library, which no environment-based sandbox in this state can reach. Use `mod.fetch` for background HTTP (`network`) or `mod.job` for background compute (`background`) — both run your code inside the sandbox instead of outside it |
 | `require("ffi")` | arbitrary C |
 | `debug`, `getfenv`, `setfenv` | each one undoes the sandbox from inside |
 | `io.popen`, `os.execute` | spawning a process |
@@ -298,7 +298,10 @@ Three consequences worth knowing before you write against it:
 - **Ship source, not bytecode.** A precompiled entry file is refused.
 
 `permissions` in the manifest is still a disclosure the manager shows the
-player, and `network` now gates `require("socket")` and friends. There is no
+player. `network` gates `require("socket")` and friends plus `mod.fetch`
+(non-blocking HTTP), and `background` gates `mod.job` (compute on a worker
+thread). Those two are the sanctioned ways to work off the main thread now
+that `love.thread` is refused. There is no
 permission that grants raw filesystem access, because no mod needs one:
 everything a mod legitimately writes is already scoped by
 `mod.storage` or the asset-transform derived root.

docs/launcher.md

@@ -16,6 +16,7 @@ save directory as:
 | nil / `"rom"` | `picked_rom.gb` (open) |
 | `"mod"` | `picked_mod.zip` (open) |
 | `"sav"` / `"save"` | `picked_save.sav` (open) |
+| `"required_import"` | `picked_required_import.bin` (open) |
 
 Export uses a separate API: `love.system.createFile(suggestedName)` →
 `GameActivity.showCreateDocument` (`ACTION_CREATE_DOCUMENT`), which copies

docs/modding.md

@@ -148,6 +148,18 @@ older iOS-only `"stadium"` picker kind remains temporarily for compatibility.
 Android now returns `false` for unknown picker kinds instead of treating them
 as game-ROM picks.
 
+### Platform import flow
+
+The same per-mod validation and private `mods/<mod-id>/baseroms/` destination
+applies on every supported platform. Windows, macOS, and Linux use the
+launcher file chooser. Android uses the Storage Access Framework, and iOS uses
+the Files document picker; both stage the choice as `picked_required_import.bin`
+before validation. Xbox/UWP uses its native picker and hands the launcher a
+temporary path. Switch/NX has no host picker, so the player copies a file to
+`imports/baseroms/` over MTP and chooses the import again. No platform grants
+the mod a host filesystem path or bypasses the manifest's size, format, and MD5
+checks.
+
 ## Mods and Gold (Gen 2)
 
 The mod API is one API across both generations, but Gold runs its own battle
@@ -803,6 +815,125 @@ own copy of a delivery, and steps are anchored natively so the same walk
 is never delivered twice. Without the permission, `sync` and `poll` raise
 an error naming it.
 
+## Background HTTP
+
+`mod.fetch` is how a mod does work off the main thread. It is behind the
+`network` permission in `manifest.json`, the same one that gates
+`require("socket")`, and the player sees it in the mod manager.
+
+```lua
+-- somewhere once
+local job = mod.fetch:get("https://example.com/data.json")
+
+-- in a hook or update, every frame -- poll never blocks
+if job then
+  local r = mod.fetch:poll(job)
+  if r.status ~= "pending" then
+    if r.status == "ok" then use(r.body) else warn(r.err) end
+    mod.fetch:release(job)
+    job = nil
+  end
+end
+```
+
+`get(url, opts)` returns an opaque handle, or `nil` plus a reason. `opts`
+takes `accept` (a request Accept header) and `maxSeconds` (clamped to 30).
+`poll(handle)` returns `{ status, body, err, progress }` where `status` is
+`"pending"`, `"ok"`, `"error"` or `"cancelled"`; it is a copy, and it never
+blocks, so calling it every frame is the intended use. `release(handle)`
+frees a finished job — do it, or you will hit the ceiling. `cancel(handle)`
+drops a result you no longer want. `available()` is `false` when the build
+has no transport and for mods without the permission, so a probe is safe.
+
+The rules worth knowing before you design around it:
+
+- **http and https only.** The underlying transport also speaks `file://`,
+  `ftp://` and `scp://`; those are refused, on the initial URL and on any
+  redirect. `mod.fetch` is not a way to read a local file.
+- **Four requests in flight per mod.** The worker pool is shared with the
+  launcher's own downloads, so one mod cannot fill it. Over the ceiling,
+  `get` returns `nil` and a reason until you release something.
+- **Handles are yours alone.** A handle from another mod, a fabricated
+  table, or a guessed number all poll as `"error"`.
+- **Your mod id is in the User-Agent**, so a server operator can see who is
+  calling and a mod cannot pose as the launcher.
+- Jobs are released when your mod unloads.
+
+This is deliberately not `love.thread`. A LÖVE thread is a fresh Lua state
+with a full standard library that the sandbox cannot reach, so handing one
+to a mod would undo every other rule; `mod.fetch`'s workers run engine
+code, so a mod gets asynchrony without gaining any new reach.
+
+## Background jobs
+
+`mod.fetch` covers work waiting on a server. `mod.job` covers work waiting on
+the CPU — generating a map, crunching a table, anything that would otherwise
+stall a frame. It is behind the `background` permission in `manifest.json`.
+
+Ship the job as its own file inside your mod:
+
+```lua
+-- mods/your_mod/jobs/crunch.lua
+local arg = ...
+local total = 0
+for i = 1, arg.n do total = total + i end
+return { total = total }
+```
+
+```lua
+-- in your entry file
+local job = mod.job:run("jobs/crunch.lua", { n = 1e6 })
+
+-- later, in a hook -- poll never blocks
+local r = mod.job:poll(job)
+if r.status == "ok" then
+  use(r.result.total)
+  mod.job:release(job)
+end
+```
+
+`run(script, arg, opts)` returns an opaque handle, or `nil` plus a reason.
+`opts.maxSeconds` sets the job's time budget (default 5, clamped to 30).
+`poll(handle)` returns `{ status, result, err }` with `status` one of
+`"pending"`, `"ok"`, `"error"` or `"cancelled"`. `release(handle)` frees it.
+`available()` is `false` on a host without threads and for mods without the
+permission, so a probe is always safe.
+
+**A job is pure compute.** This is the part to design around, not a detail:
+
+- **Plain data in, plain data out.** Numbers, strings, booleans and tables of
+  them. A function, userdata, a cycle or a table key that is not a string or
+  number is refused at your `run` call with a reason. Nothing is shared —
+  your argument is snapshotted, and mutating the original afterwards does not
+  reach the job.
+- **No engine API, no game state, no storage.** `require` is refused inside a
+  job, and there is no `mod` object. A job cannot read the party, write
+  `mod.storage`, or touch a registry. Get what it needs into the argument and
+  act on the result back on the main thread.
+- **Your script is a file in your mod folder.** The path goes through the same
+  rules as `mod:read`; `..`, absolute paths and drive letters are refused.
+- **Two jobs per mod, four on the machine.** Over the limit, `run` returns
+  `nil` and a reason until you release one.
+- **The budget bounds how long YOU wait, not how long the work runs.** Past
+  `maxSeconds`, `poll` reports an error and the result is dropped if it ever
+  arrives — but the thread runs to its own end. There is no way to stop a
+  LÖVE thread from outside, and every attempt to stop one from inside was
+  worse than the disease (a debug hook does not reliably interrupt LuaJIT,
+  and raising from one wedged the whole process). `cancel(handle)` is the
+  same deal: it drops the result, it does not stop the work.
+
+  So **write jobs that terminate.** A job with an infinite loop will keep one
+  core busy until the game closes. It will not freeze the game — the main
+  thread stays responsive and quitting still works — but nothing will reclaim
+  that core in the meantime.
+
+Your job script runs in the same sandbox your entry file does, so `io`, `os`,
+`debug`, `ffi`, `package` and `love.filesystem` are absent there too. That is
+the whole reason this exists rather than `love.thread`: a raw LÖVE thread is a
+fresh Lua state with a full standard library that the sandbox cannot reach, so
+handing one to a mod would undo every other rule. Here the worker builds your
+sandbox first and loads your chunk into it.
+
 ## Pre-sandbox globals (compat)
 
 A mod written before the sandbox landed does not have to be updated to
@@ -835,4 +966,5 @@ with the full standard library, which the sandbox in this state cannot
 reach, so a stand-in would be a hole rather than a reroute. The same goes
 for `ffi`, `debug`, `setfenv`, `os.execute`, `io.popen`, `love.run` and
 `love.errorhandler`. A mod that needs real background work needs an
-engine-owned facility, not a compat shim.
+engine-owned facility, not a compat shim -- for HTTP that facility is
+[`mod.fetch`](#modfetch), which runs on the engine's own worker pool.

docs/new-features.md

@@ -19,7 +19,7 @@ Features intentionally added beyond the original Pokémon Red, Blue, and Yellow
 * **Soft reset button combination**
 * **Keyboard and controller rebinding**
 * **Mod profiles** with separate mod settings and save slots
-* **Sandboxed mods**: an installed mod can read only its own folder and write only its own storage, so it cannot reach the rest of your device
+* **Sandboxed mods**: an installed mod can read only its own folder and write only its own storage, so it cannot reach the rest of your device, and mods that need the internet or heavy background work do it through permissions the mod manager shows you, without freezing the game
 * **Improved launcher and save editor UI**, including background downloads and update checks
 * **Direct-launch options** for shortcuts, Steam entries, and handheld frontends
 * **Custom boot branding**

docs/updater.md

@@ -126,11 +126,19 @@ bundled game, in that case.
   already driving the frame. A payload that must change `love.run` itself
   needs a `minShell` bump so an older shell refuses to chainload it rather
   than running with half its intended behavior.
-- **Android has no in-app download transport yet.** `check_worker.lua`
-  shells out to curl for both the release check and the download; curl is
-  absent on Android, so `Check` degrades to `status = "error"` there (the
-  launcher UI hides on that status) and the player is directed to the
-  releases page via `Check.releaseUrl()` instead.
+- **Android and iOS use the native download bridge, not curl.** Neither
+  platform ships curl, so the old `check_worker.lua` path (shell out to curl)
+  always landed on `error` and the launcher chip's "Check for updates" tap
+  was a no-op. The worker now talks through `HostShell`, the same transport
+  as the mod catalog: curl on desktop, `love.system.httpDownload` on mobile.
+  On Android that is the GameActivity JNI/`HttpsURLConnection` bridge; on
+  iOS it is `GRPickerBridge.httpDownload` (`URLSession`). A fused sideloaded
+  APK or IPA can therefore check GitHub and fetch the `.love` payload
+  in-app. If neither transport exists, the worker reports `needs_full` and
+  the launcher chip opens `Check.releaseUrl()`. Native package-only changes
+  still need a full reinstall (`minShell` / `payloadHost` gate →
+  `needs_full`). Applying a downloaded payload on Android relaunches via
+  `love.system.restartApp`; iOS still uses in-process `quit("restart")`.
 - **Dev/source runs never self-update.** `Boot.run` returns immediately when
   `love.filesystem.isFused()` is false, and a working tree's `engine` is the
   `"0.0.0-dev"` placeholder that always reports up to date, so a source

main.lua

@@ -148,9 +148,44 @@ local function openEditor(version, slotId)
   editorMode = true
   resizeForEditor()
   addEditorRequirePath()
-  EditorApp = require("App")
-  EditorApp.load(path, { version = version, slotId = slotId, embedded = true,
-                         onClose = function() closeEditor() end })
+  local okReq, appOrErr = pcall(require, "App")
+  if not okReq then
+    editorMode = false
+    if version then
+      require("src.import.CacheFs").unmountVersion(version)
+    end
+    restoreWindow()
+    Importer = editorHost
+    editorHost = nil
+    editorVersion = nil
+    if Importer and Importer.resumeAfterOverlay then
+      Importer:resumeAfterOverlay()
+    end
+    refuse("Could not open the save editor (" .. tostring(appOrErr) .. ").")
+    return
+  end
+  EditorApp = appOrErr
+  local okLoad, loadErr = pcall(EditorApp.load, path, {
+    version = version, slotId = slotId, embedded = true,
+    onClose = function() closeEditor() end,
+  })
+  if not okLoad then
+    editorMode = false
+    if EditorApp.unload then pcall(EditorApp.unload) end
+    EditorApp = nil
+    if version then
+      require("src.import.CacheFs").unmountVersion(version)
+      require("src.core.Data"):unloadGenerated()
+    end
+    restoreWindow()
+    Importer = editorHost
+    editorHost = nil
+    editorVersion = nil
+    if Importer and Importer.resumeAfterOverlay then
+      Importer:resumeAfterOverlay()
+    end
+    refuse("Could not open the save editor (" .. tostring(loadErr) .. ").")
+  end
 end
 
 -- Back to the launcher.  Everything the editor mounted or cached has to come
@@ -166,6 +201,11 @@ function closeEditor()
     require("src.import.CacheFs").unmountVersion(version)
     require("src.core.Data"):unloadGenerated()
   end
+  for k in pairs(package.loaded) do
+    if type(k) == "string" and (k:find("save%-editor") or k == "App" or k == "Kit" or k == "State" or k == "Catalog" or k == "SaveIO" or k == "Ops" or k == "MonOps" or k == "ItemOps" or k == "PadInput" or k == "Gen" or k == "Theme") then
+      package.loaded[k] = nil
+    end
+  end
   editorVersion = nil
   restoreWindow()
   Importer = editorHost
@@ -263,6 +303,11 @@ function love.load(args)
   -- of each flashing their own cmd.exe window (#606).  No-op elsewhere.
   require("src.core.HostShell").hideHostConsole()
 
+  -- Hang gen1tls on love.system before mods boot.  Android already has tls*
+  -- from JNI; this is the desktop half.  No DLL / no FFI is fine -- ws://
+  -- rooms still work, wss:// just won't.
+  pcall(function() require("src.net.Gen1Tls").install() end)
+
   -- NX fused mounts are unreliable for the blue|yellow cache overlay: wrap
   -- the love loaders once so every generated-asset read falls back to the
   -- versioned save-dir copy.  Never installed on desktop/Android/iOS.

mobile/android/love/src/main/java/org/love2d/android/GameActivity.java

@@ -90,6 +90,9 @@ public class GameActivity extends SDLActivity {
     private static final String PICKED_ROM_FILENAME = "picked_rom.gb";
     private static final String PICKED_MOD_FILENAME = "picked_mod.zip";
     private static final String PICKED_SAVE_FILENAME = "picked_save.sav";
+    // Kept separate from the game-ROM destination so a dependency pick can
+    // never be mistaken for a game import when the picker returns on Android.
+    private static final String PICKED_REQUIRED_IMPORT_FILENAME = "picked_required_import.bin";
     private static final String PENDING_EXPORT_FILENAME = "pending_export.sav";
     private static final String EXPORT_DONE_FILENAME = "export_done.flag";
     // Written when a SAF pick cannot be read at all, with the destination
@@ -504,7 +507,8 @@ public class GameActivity extends SDLActivity {
      * picker-agnostic and unchanged.
      *
      * @param destFilename basename under the app save identity (e.g.
-     *                     picked_rom.gb, picked_mod.zip, picked_save.sav)
+     *                     picked_rom.gb, picked_mod.zip, picked_save.sav, or
+     *                     picked_required_import.bin)
      */
     /** Legacy single-argument entry; resolves the save dir itself. */
     @Keep
@@ -535,6 +539,11 @@ public class GameActivity extends SDLActivity {
             Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
             intent.addCategory(Intent.CATEGORY_OPENABLE);
             intent.setType("*/*");
+            // The Storage Access Framework grants the returned content URI
+            // directly to this activity. Request the read grant explicitly as
+            // well: Android 13's scoped storage deliberately does not expose
+            // arbitrary paths or require broad media/storage permissions.
+            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
             try {
                 self.startActivityForResult(intent, FILE_PICKER_REQUEST_CODE);
                 return true;
@@ -547,6 +556,7 @@ public class GameActivity extends SDLActivity {
         Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
         intent.addCategory(Intent.CATEGORY_OPENABLE);
         intent.setType("*/*");
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
         try {
             self.startActivityForResult(
                 Intent.createChooser(intent, "Choose a file"),
@@ -576,6 +586,12 @@ public class GameActivity extends SDLActivity {
         return showFilePicker(PICKED_SAVE_FILENAME);
     }
 
+    /** Required-mod-file wrapper used by love.system.pickFile("required_import"). */
+    @Keep
+    public static boolean showRequiredImportFilePicker() {
+        return showFilePicker(PICKED_REQUIRED_IMPORT_FILENAME);
+    }
+
     /**
      * Relaunches the whole app for love.system.restartApp, used by
      * src/core/HostShell.lua when a mod toggle needs a cold boot (#575).

mobile/ios/app-repo.json

@@ -12,6 +12,20 @@
       "tintColor": "3b5ca8",
       "category": "games",
       "versions": [
+        {
+          "version": "0.1.92",
+          "date": "2026-08-15",
+          "size": 11364274,
+          "downloadURL": "https://github.com/bryanthaboi/gen1recomp/releases/download/v0.1.92/gen1recomp++-0.1.92-ios.ipa",
+          "localizedDescription": "Download the correct version for your computer below.\n\n## Contributors\n\n- @bryanthaboi"
+        },
+        {
+          "version": "0.1.91",
+          "date": "2026-08-15",
+          "size": 11351477,
+          "downloadURL": "https://github.com/bryanthaboi/gen1recomp/releases/download/v0.1.91/gen1recomp++-0.1.91-ios.ipa",
+          "localizedDescription": "Download the correct version for your computer below.\n\n## Contributors\n\n- @bryanthaboi"
+        },
         {
           "version": "0.1.90",
           "date": "2026-08-15",

src/core/Data.lua

@@ -14,6 +14,14 @@ local MODULES = {
 -- Optional for compatibility with developer and stale caches.
 local OPTIONAL = { "audio", "palettes", "icons" }
 
+-- Gold's extractor never writes these Gen 1 tables (RomExtractorGen2 has
+-- maps/text/pokemon/items, not text_pointers / trainer_headers / field).
+-- Desktop can still `require` Red's copies from the source tree, so Gold
+-- Edit appeared to work there; an Android APK has only the per-version
+-- cache, so Data:load used to throw on the first Gold Edit and take the
+-- activity down.  Empty tables are enough for seedDefaults / the editor.
+local GEN2_OPTIONAL = { text_pointers = true, trainer_headers = true, field = true }
+
 -- Vanilla defaults for rules exposed through the constants registry.  A
 -- value has to exist before a mod can patch it; each one matches the
 -- engine's no-mod behavior, so seeding them changes nothing on a vanilla
@@ -99,7 +107,11 @@ end
 -- Fills only what the cache is missing, so an importer that learns to
 -- stamp one of these keys silently takes over from the engine.
 function Data:seedDefaults()
-  local constants = self.constants
+  local constants = self.constants or {}
+  self.constants = constants
+  self.field = self.field or {}
+  self.maps = self.maps or {}
+  self.pokemon = self.pokemon or {}
   for key, value in pairs(CONSTANT_DEFAULTS) do
     if constants[key] == nil then constants[key] = copy(value) end
   end
@@ -108,7 +120,11 @@ function Data:seedDefaults()
   if constants.dexSize == nil then
     local highest = 0
     for _, def in pairs(self.pokemon) do
-      if def.dex and def.dex > highest then highest = def.dex end
+      -- Gold's pokemon.lua also carries growthRates / tmhmMoves / generation
+      -- scalars beside species rows.
+      if type(def) == "table" and def.dex and def.dex > highest then
+        highest = def.dex
+      end
     end
     constants.dexSize = highest
   end
@@ -212,36 +228,41 @@ local function loadModule(dir, name)
     if not chunk then return false, err end
     return pcall(chunk)
   end
-  local ok, mod = pcall(require, "data.generated." .. name)
-  if ok then return true, mod end
-  -- Fused PhysFS / Blue|Yellow prefix: load bytes from the active version's
-  -- cache explicitly when require cannot see the mounted tree.
   local CacheFs = require("src.import.CacheFs")
   local GameVersion = require("src.core.GameVersion")
   local path = "data/generated/" .. name .. ".lua"
   local bytes = CacheFs.readActive(path)
   if type(bytes) == "string" then
-    local chunk, err = loadstring(bytes, "@" .. GameVersion.cachePrefix() .. path)
-    if not chunk then return false, err or mod end
-    return pcall(chunk)
+    local chunk = loadstring(bytes, "@" .. GameVersion.cachePrefix() .. path)
+    if chunk then
+      local ok, res = pcall(chunk)
+      if ok then return true, res end
+    end
   end
-  return false, mod
+  local ok, mod = pcall(require, "data.generated." .. name)
+  if ok then return true, mod end
+  return false, nil
 end
 
 function Data:load()
   local dir = os.getenv("POKEPORT_DATA_DIR")
+  local gen2 = require("src.core.GameVersion").generation() == 2
   for _, name in ipairs(MODULES) do
     local ok, mod = loadModule(dir, name)
     if not ok then
-      if dir then
+      if gen2 and GEN2_OPTIONAL[name] then
+        self[name] = {}
+      elseif dir then
         error(("missing data module '%s/%s.lua' (POKEPORT_DATA_DIR).\n(%s)")
               :format(dir, name, mod))
+      else
+        error(("missing generated data module 'data/generated/%s.lua'.\n" ..
+               "Import the ROM again or rebuild developer data.\n(%s)")
+              :format(name, mod))
       end
-      error(("missing generated data module 'data/generated/%s.lua'.\n" ..
-             "Import the ROM again or rebuild developer data.\n(%s)")
-            :format(name, mod))
+    else
+      self[name] = mod
     end
-    self[name] = mod
   end
   for _, name in ipairs(OPTIONAL) do
     local ok, mod = loadModule(dir, name)
@@ -280,11 +301,14 @@ function Data:unloadGenerated()
       if not pristine[key] then self[key] = nil end
     end
   end
+  self._pristineKeys = nil
   for _, name in ipairs(MODULES) do
     package.loaded["data.generated." .. name] = nil
+    self[name] = nil
   end
   for _, name in ipairs(OPTIONAL) do
     package.loaded["data.generated." .. name] = nil
+    self[name] = nil
   end
 end
 

src/core/HostShell.lua

@@ -325,7 +325,8 @@ function HostShell.httpDownload(url, absPath, userAgent, accept, maxTime)
   if type(absPath) ~= "string" or absPath == "" then return nil, "missing path" end
   userAgent = userAgent or "gen1recomp"
   if HostShell.haveCurl() then
-    local cmd = ("curl -fsSL --connect-timeout 15 --max-time %d ")
+    local cmd = ("curl -fsSL --proto =http,https --proto-redir =http,https "
+      .. "--connect-timeout 15 --max-time %d ")
       :format(tonumber(maxTime) or 300)
       .. "-H " .. HostShell.quote("User-Agent: " .. userAgent) .. " "
     if accept then
@@ -370,7 +371,8 @@ function HostShell.httpGet(url, userAgent, accept, maxTime)
     -- BODY, and on the two services this talks to that body is the whole
     -- diagnosis: GitHub's 403 says "API rate limit exceeded for <ip>", which
     -- tells a user to wait rather than to go hunting for a broken index.
-    local cmd = ("curl -sSL --connect-timeout 10 --max-time %d ")
+    local cmd = ("curl -sSL --proto =http,https --proto-redir =http,https "
+      .. "--connect-timeout 10 --max-time %d ")
       :format(tonumber(maxTime) or 40)
       .. "-H " .. HostShell.quote("User-Agent: " .. userAgent) .. " "
     if accept then

src/import/ExtractThread.lua

@@ -0,0 +1,50 @@
+-- ROM extraction, off the main thread.  The extractor's require closure needs
+-- only love.filesystem, love.image, love.math and love.system, none of which
+-- are main-thread-only, so it runs here instead of as a coroutine the frame
+-- loop resumed for 8ms out of every 16.7ms.
+--
+-- The caller clears the stale cache and writes the completion marker itself;
+-- this only fills the tree between those two steps, so the "marker appears
+-- last" order isReady() depends on stays on one thread.
+
+require("love.filesystem")
+require("love.image")
+require("love.math")
+require("love.system")
+require("love.timer")
+
+local version, prefix, romData, progressName, resultName = ...
+
+local progressChannel = love.thread.getChannel(progressName)
+local resultChannel = love.thread.getChannel(resultName)
+
+-- RomExtractor:tick fires per item, thousands of times per import; a channel
+-- push each would cost more than the work it reports.
+local PROGRESS_HZ = 20
+
+local ok, err = pcall(function()
+  local CacheFs = require("src.import.CacheFs")
+  CacheFs.prefix = prefix
+
+  local manifest = require("src.import.RomManifest").decode(version)
+  local RomExtractor = version == "gold"
+    and require("src.import.RomExtractorGen2")
+    or require("src.import.RomExtractor")
+
+  local lastPush, lastStage = 0, nil
+  local extractor = RomExtractor.new(romData, manifest,
+    function(progress, total, stage, current, stageTotal)
+      local now = love.timer.getTime()
+      -- Stage changes always go through, or the caption goes stale.
+      if stage ~= lastStage or now - lastPush >= 1 / PROGRESS_HZ then
+        lastPush, lastStage = now, stage
+        progressChannel:push({
+          progress = progress, total = total, stage = stage,
+          current = current, stageTotal = stageTotal,
+        })
+      end
+    end)
+  extractor:run()
+end)
+
+resultChannel:push({ ok = ok, error = ok and nil or tostring(err) })

src/import/LauncherView.lua

@@ -299,11 +299,6 @@ end
 
 local CART_DRAG_SLOP = 8
 local TAU = math.pi * 2
--- The 3D mesh is inset inside the hit box so yaw/pitch and the 1.05 hover
--- scale cannot climb into the title row (or the gear) on desktop, high-DPI,
--- or a portrait phone.  Fraction of the shorter side, with a pixel floor.
-local CART_MESH_PAD = 0.07
-local CART_MESH_PAD_MIN = 8
 
 local function cartridgeState(imp, version)
   imp._cartridge = imp._cartridge or {}
@@ -548,11 +543,8 @@ local function cartridgeButton(imp, x, y, w, h, key, version, gameName, action)
       Theme.A.focus, 2, Theme.cardRadius() + 2)
   end
 
-  local meshPad = math.max(CART_MESH_PAD_MIN,
-    math.floor(math.min(w, h) * CART_MESH_PAD))
-  local halfW = math.max(1, w / 2 - meshPad)
-  local halfH = math.max(1, h / 2 - meshPad)
-  local depth = math.max(8, (halfW * 2) * 0.14)
+  local halfW, halfH = w / 2, h / 2
+  local depth = math.max(8, w * 0.14)
   local project = function(px, py, pz)
     return cartProject(cx + pressX, cy + pressY, yaw, pitch,
       px * pressedScale, py * pressedScale, pz * pressedScale)
@@ -811,6 +803,49 @@ end
 -- Returns the y at which content may start.  Its vertical arithmetic is
 -- mirrored by headerHeight() at the bottom of this file (the short-window
 -- scroll decision needs the height before anything draws) -- keep in sync.
+-- Header chrome is fixed: the same six tabs, the same gear and Quit, every
+-- frame.  Their tab rows, opts tables and action closures are built once
+-- instead of 60 times a second -- only `active`, `image` and the queued
+-- action are written per frame.
+local HEADER_TABS = {
+  { id = "red",    key = "tab-red",    letter = "R", color = PAL.railRed },
+  { id = "blue",   key = "tab-blue",   letter = "B", color = PAL.railBlue },
+  { id = "yellow", key = "tab-yellow", letter = "Y", color = PAL.railGold },
+  { id = "gold",   key = "tab-gold",   letter = "G", color = PAL.railAmber },
+  { id = "mods",   key = "tab-mods" },
+  { id = "find",   key = "tab-find" },
+}
+for _, t in ipairs(HEADER_TABS) do
+  t.opts = { face = "tab", font = "tab", color = t.color, letter = t.letter }
+end
+
+local QUIT_INK_HOT = { 0, 0, 0, 1 }
+local QUIT_INK_REST = { 1, 1, 1, 0.85 }
+
+-- Keyed off the launcher instance so the closures die with it.
+local function headerChrome(imp)
+  local c = imp._headerChrome
+  if c then return c end
+  c = {
+    gear = { face = "invert",
+      action = function() imp:_openSettings() end },
+    quit = { face = "invert",
+      action = function() imp:_quitApp() end,
+      drawFn = function(x, y, w, h, hot)
+        local pad = math.floor(w * 0.32)
+        drawCross(x + pad, y + pad, w - 2 * pad,
+          hot and QUIT_INK_HOT or QUIT_INK_REST)
+      end },
+    tab = {},
+  }
+  for _, t in ipairs(HEADER_TABS) do
+    local id = t.id
+    c.tab[id] = function() imp:_switchTab(id) end
+  end
+  imp._headerChrome = c
+  return c
+end
+
 local function buildHeader(imp, m)
   local y = m.top
   Theme.versionRail(m.x, y, m.w, m.railH)
@@ -869,20 +904,11 @@ local function buildHeader(imp, m)
   imp._gearIcon = imp._gearIcon
     or love.graphics.newImage("assets/launcher/gear.png")
   rx = rx - gear
-  btn(imp, rx, by, gear, gear, "gear", "", {
-    face = "invert", image = imp._gearIcon,
-    action = function() imp:_openSettings() end,
-  })
+  local chrome = headerChrome(imp)
+  chrome.gear.image = imp._gearIcon
+  btn(imp, rx, by, gear, gear, "gear", "", chrome.gear)
 
-  btn(imp, quitX, by, gear, gear, "quit", "", {
-    face = "invert",
-    action = function() imp:_quitApp() end,
-    drawFn = function(x, y, w, h, hot)
-      local pad = math.floor(w * 0.32)
-      drawCross(x + pad, y + pad, w - 2 * pad,
-        hot and { 0, 0, 0, 1 } or { 1, 1, 1, 0.85 })
-    end,
-  })
+  btn(imp, quitX, by, gear, gear, "quit", "", chrome.quit)
 
   -- The self-update control lives in the FOOTER next to the BCG mark (small,
   -- out of the wordmark's way -- it used to overlap the logo on a phone).  It
@@ -900,14 +926,8 @@ local function buildHeader(imp, m)
   -- the fill when active, the same rule the buttons follow.  Yellow stays the
   -- bright cart gold; Gold (Gen 2) uses the deeper amber so the two do not
   -- collide.
-  local tabs = {
-    { id = "red",    letter = "R", color = PAL.railRed },
-    { id = "blue",   letter = "B", color = PAL.railBlue },
-    { id = "yellow", letter = "Y", color = PAL.railGold },
-    { id = "gold",   letter = "G", color = PAL.railAmber },
-    { id = "mods",   icon = imp._modsIcon },
-    { id = "find",   icon = imp._findIcon },
-  }
+  local tabs = HEADER_TABS
+  tabs[5].icon, tabs[6].icon = imp._modsIcon, imp._findIcon
   local tabH = m.chip
   local tx = m.x + m.pad
   local ty = y + math.floor(6 * m.s)
@@ -916,18 +936,16 @@ local function buildHeader(imp, m)
   local tabGap = math.floor(6 * m.s)
   local tabRowGap = math.floor(4 * m.s)
   for _, t in ipairs(tabs) do
-    local active = imp.tab == t.id
-    local key = "tab-" .. t.id
     local w = tabH
     if tx > tabLeft and tx + w > tabRight then
       tx = tabLeft
       ty = ty + tabH + tabRowGap
     end
-    btn(imp, tx, ty, w, tabH, key, "", {
-      face = "tab", font = "tab", color = t.color, active = active,
-      image = t.icon, letter = t.letter,
-      action = function() imp:_switchTab(t.id) end,
-    })
+    local o = t.opts
+    o.active = imp.tab == t.id
+    o.image = t.icon
+    o.action = chrome.tab[t.id]
+    btn(imp, tx, ty, w, tabH, t.key, "", o)
     tx = tx + w + tabGap
   end
 
@@ -1477,6 +1495,20 @@ end
 -- gets whatever width the previous ones left, and the first segment that has
 -- to ellipsize ends the line.  Lets the download count sit green inside an
 -- otherwise muted stats line without two competing ellipsis passes.
+-- A row's control key is a pure function of its id, but concatenating it per
+-- visible row per frame is ~1200 strings a second.  Memoised on the launcher,
+-- NOT on the entry: index entries are the same tables ModIndex.writeCache
+-- persists into options.modIndexCache, and view state must not ride along.
+local function rowKeyFor(imp, prefix, id)
+  local keys = imp._rowKeys
+  if not keys then keys = {}; imp._rowKeys = keys end
+  local byPrefix = keys[prefix]
+  if not byPrefix then byPrefix = {}; keys[prefix] = byPrefix end
+  local key = byPrefix[id]
+  if not key then key = prefix .. tostring(id); byPrefix[id] = key end
+  return key
+end
+
 local function segLine(fontName, segs, x, y, maxW)
   local sx = x
   for _, seg in ipairs(segs) do
@@ -1502,6 +1534,55 @@ local function sortDefs()
   }
 end
 
+-- Sorting is decorate-sort-undecorate: the key is computed once per entry
+-- instead of the 2*n*log(n) times a comparator that derives it would, and the
+-- comparator itself is a module-level function so no closure is allocated per
+-- comparison.  Measured on a synthetic index: 500 entries went from 8,964 key
+-- computations and 4,482 closures to 500 and none.
+local sortAsc = true
+
+local function decCompare(a, b)
+  if a.k ~= b.k then
+    if sortAsc then return a.k < b.k end
+    return a.k > b.k   -- data sorts newest / most popular first
+  end
+  return a.tie < b.tie
+end
+
+-- Fill `scratch` with one { e, k, tie } slot per entry, reusing the slots.
+local function decorate(scratch, src, keyOf, tieOf)
+  local n = #src
+  for i = 1, n do
+    local e = src[i]
+    local slot = scratch[i]
+    if not slot then slot = {}; scratch[i] = slot end
+    slot.e, slot.tie = e, tieOf(e)
+    slot.k = keyOf(e, slot.tie)
+  end
+  for i = #scratch, n + 1, -1 do scratch[i] = nil end
+  return n
+end
+
+local function undecorate(scratch, n)
+  local out = {}
+  for i = 1, n do out[i] = scratch[i].e end
+  return out
+end
+
+-- While results are still streaming in, re-ordering on every arrival re-sorts
+-- the whole list every frame and makes rows jump under the reader.  Hold the
+-- current order this long and take the change in one pass.
+local RESORT_DEBOUNCE = 0.25
+
+-- True when the cached order is still good.  `rev` is only part of the key
+-- for a stats-dependent sort: Name order does not depend on release data, so
+-- a stats arrival used to invalidate a sort whose result could not change.
+local function sortCacheOk(cache, src, key, rev, pending)
+  if not (cache and cache.src == src and cache.key == key) then return false end
+  if cache.rev == rev then return true end
+  return pending and (Kit.time - (cache.at or 0)) < RESORT_DEBOUNCE
+end
+
 local function currentSort(imp)
   local sortKey = imp.modSort
   if sortKey == nil then
@@ -1643,16 +1724,18 @@ local function buildModsPanel(imp, x, y, w, availH, m)
   -- per frame (with lowercased-string allocations in the comparator) fed the
   -- GC for nothing.  Cache the sorted array, keyed on the list identity, the
   -- sort mode, and the update-info revision the fetch pump bumps.
+  local statsSort = sortKey ~= "name"
+  local rev = statsSort and (imp._modUpdateRev or 0) or 0
   local cache = imp._modSortCache
-  if cache and cache.src == mods and cache.n == #mods
-      and cache.key == sortKey and cache.rev == (imp._modUpdateRev or 0) then
+  if cache and cache.n == #mods
+      and sortCacheOk(cache, mods, sortKey, rev, imp._modInfoFetch ~= nil) then
     mods = cache.list
   else
-    local sorted = {}
-    for i, v in ipairs(mods) do sorted[i] = v end
-    table.sort(sorted, function(a, b)
-      local function value(mod)
-        if sortKey == "name" then return (mod.name or ""):lower() end
+    local scratch = imp._modSortScratch or {}
+    imp._modSortScratch = scratch
+    local n = decorate(scratch, mods,
+      function(mod, tie)
+        if sortKey == "name" then return tie end
         local info = mod.github and mod.github ~= "" and imp:_modUpdateInfo(mod.id)
         if sortKey == "popularity" then
           return info and info.downloads and info.downloads.total or -1
@@ -1660,16 +1743,13 @@ local function buildModsPanel(imp, x, y, w, availH, m)
         local date = info and info.dates
         if sortKey == "release" then return date and date.first or "0000-00-00" end
         return date and date.latest or "0000-00-00"
-      end
-      local va, vb = value(a), value(b)
-      if va ~= vb then
-        if sortKey == "name" then return va < vb end
-        return va > vb  -- data sorts newest / most popular first
-      end
-      return (a.name or ""):lower() < (b.name or ""):lower()
-    end)
-    imp._modSortCache = { src = imp.mods, n = #mods, key = sortKey,
-      rev = imp._modUpdateRev or 0, list = sorted }
+      end,
+      function(mod) return (mod.name or ""):lower() end)
+    sortAsc = sortKey == "name"
+    table.sort(scratch, decCompare)
+    local sorted = undecorate(scratch, n)
+    imp._modSortCache = { src = mods, n = #mods, key = sortKey,
+      rev = rev, at = Kit.time, list = sorted }
     mods = sorted
   end
 
@@ -1692,7 +1772,9 @@ local function buildModsPanel(imp, x, y, w, availH, m)
   local contentH = shown * rowH + math.max(0, shown - 1) * gap
   local scrollMax = math.max(0, contentH - listH)
   local scroll = clamp(imp.modScroll or 0, 0, scrollMax)
-  imp._modListRect = { x = x, y = listTop, w = w, h = listH }
+  local lr = imp._modListRect
+  if not lr then lr = {}; imp._modListRect = lr end
+  lr.x, lr.y, lr.w, lr.h = x, listTop, w, listH
   imp._modScrollMax = scrollMax
   if scrollMax > 0 and (Kit.wheelY or 0) ~= 0 and Kit.hit(x, listTop, w, listH) then
     scroll = clamp(scroll - Kit.wheelY * math.floor(48 * m.s), 0, scrollMax)
@@ -1708,7 +1790,7 @@ local function buildModsPanel(imp, x, y, w, availH, m)
   for i = first, last do
     local mod = mods[i]
     local ry = listTop + (i - first) * (rowH + gap) - scroll
-    local rowKey = "mod-row-" .. mod.id
+    local rowKey = rowKeyFor(imp, "mod-row-", mod.id)
     local isFullyDisabled = true
     if mod.enabledByVersion then
       for _, on in pairs(mod.enabledByVersion) do
@@ -1900,30 +1982,30 @@ local function buildFindPanel(imp, x, y, w, availH, m)
 
   -- Same caching rule as the MODS tab: the comparator allocates, so only
   -- re-sort when the inputs actually change.
+  local statsSort = sortKey ~= "name"
+  local rev = statsSort and (imp._findStatsRev or 0) or 0
   local fcache = imp._findSortCache
-  if fcache and fcache.src == rows and fcache.key == sortKey
-      and fcache.rev == (imp._findStatsRev or 0) then
+  if sortCacheOk(fcache, rows, sortKey, rev, imp._findStatsPending ~= nil) then
     rows = fcache.list
   else
-    local sorted = {}
-    for i, v in ipairs(rows) do sorted[i] = v end
-    table.sort(sorted, function(a, b)
-      local function value(entry)
-        if sortKey == "name" then return (entry.title or entry.id or ""):lower() end
-        local stats = imp:_findStats(entry)
+    local scratch = imp._findSortScratch or {}
+    imp._findSortScratch = scratch
+    local n = decorate(scratch, rows,
+      function(entry, tie)
+        if sortKey == "name" then return tie end
+        -- The CACHED read, never the requesting one: a sort must not queue a
+        -- fetch for every entry in the index (see _findStatsCached).
+        local stats = imp:_findStatsCached(entry)
         if sortKey == "popularity" then return stats and stats.total or -1 end
         if sortKey == "release" then return stats and stats.first or "0000-00-00" end
         return stats and stats.latest or "0000-00-00"
-      end
-      local va, vb = value(a), value(b)
-      if va ~= vb then
-        if sortKey == "name" then return va < vb end
-        return va > vb
-      end
-      return (a.title or a.id or ""):lower() < (b.title or b.id or ""):lower()
-    end)
-    imp._findSortCache = { src = rows, key = sortKey,
-      rev = imp._findStatsRev or 0, list = sorted }
+      end,
+      function(entry) return (entry.title or entry.id or ""):lower() end)
+    sortAsc = sortKey == "name"
+    table.sort(scratch, decCompare)
+    local sorted = undecorate(scratch, n)
+    imp._findSortCache = { src = rows, key = sortKey, rev = rev,
+      at = Kit.time, list = sorted }
     rows = sorted
   end
 
@@ -1952,7 +2034,7 @@ local function buildFindPanel(imp, x, y, w, availH, m)
   for i = first, last do
     local entry = rows[i]
     local ry = listTop + (i - first) * (rowH + gap)
-    local rowKey = "find-row-" .. entry.id
+    local rowKey = rowKeyFor(imp, "find-row-", entry.id)
     -- The whole row is the control: it opens the per-mod popup where
     -- Install / Details / Source moved.  The only inline signal left is a
     -- green check when the mod is already installed.
@@ -1985,8 +2067,15 @@ local function buildFindPanel(imp, x, y, w, availH, m)
       love.graphics.draw(image, Theme.snap(px), Theme.snap(ly), 0, s, s)
     else
       Theme.stroke(px, ly, thumb, thumb, PAL.line, Theme.A.hairline, 1)
-      Kit.textCenter("micro", "MOD", px,
-        ly + (thumb - Kit.textHeight("micro")) / 2, thumb, PAL.faint)
+      -- A thumbnail still downloading and one that will never arrive drew the
+      -- same dead box, so a slow index looked broken.  Spin while it is in
+      -- flight; only fall back to the wordmark once it has resolved.
+      if imp:_findThumbPending(entry.id) then
+        Kit.spinner(px + thumb / 2, ly + thumb / 2, thumb * 0.28)
+      else
+        Kit.textCenter("micro", "MOD", px,
+          ly + (thumb - Kit.textHeight("micro")) / 2, thumb, PAL.faint)
+      end
     end
 
     local bx = px + thumb + math.floor(10 * m.s)
@@ -2020,10 +2109,35 @@ local function buildFindPanel(imp, x, y, w, availH, m)
       segs[#segs + 1] = { "  -  " .. table.concat(rest, "  -  "), baseCol }
     end
     segLine("small", segs, bx, by2, bw)
+    -- The stats line used to simply be absent until the release check landed,
+    -- so rows silently changed under the reader and a slow check was
+    -- indistinguishable from a mod with no data.  Say which it is, the way
+    -- the MODS tab already does on its own rows.
+    if not stats and imp:_findStatsPendingFor(entry.id) then
+      local sw = Kit.textWidth("small", segs[1][1]) + math.floor(12 * m.s)
+      local dh = Kit.textHeight("small")
+      Loader.dot(bx + sw, by2, dh)
+      Kit.text("small", Strings("Checking..."),
+        bx + sw + dh + math.floor(6 * m.s), by2, PAL.muted)
+    end
   end
 
   local pagerY = listTop + (last - first + 1) * (rowH + gap)
   setPage(imp, "find", Kit.pager(x, pagerY, w, cur, #rows, perPage, "find"))
+
+  -- Aggregate progress.  Enrichment happens a page at a time and each row says
+  -- so for itself, but with nothing summarising it the panel looked idle while
+  -- work was in flight.  Only drawn while something is actually pending.
+  local waiting = imp:_findStatsPendingCount()
+  if waiting > 0 then
+    local py = pagerY + math.max(Kit.tapMin(), math.floor(30 * m.s))
+      + math.floor(4 * m.s)
+    local dh = Kit.textHeight("micro")
+    Loader.dot(x, py, dh)
+    Kit.text("micro", Strings("Checking %d of %d on this page...",
+      waiting, last - first + 1),
+      x + dh + math.floor(6 * m.s), py, PAL.muted)
+  end
 end
 
 -- ------------------------------------------------------------------ footer
@@ -3770,11 +3884,14 @@ function LauncherView.draw(imp)
   -- one is up; buildModals lowers the shield for the modal's own controls.
   Kit.blockClicks = modalUp(imp)
 
-  local ms = m
-  if scroll > 0 then
-    ms = setmetatable({ top = m.top - scroll }, { __index = m })
-  end
-  local contentY = buildHeader(imp, ms)
+  -- The header is the only block that moves with the page scroll, so shift
+  -- m.top across the call and put it back rather than wrapping `m` in a
+  -- proxy: the proxy cost two tables a frame and put a metatable lookup on
+  -- every m.* read for the rest of the frame.
+  local baseTop = m.top
+  if scroll > 0 then m.top = baseTop - scroll end
+  local contentY = buildHeader(imp, m)
+  m.top = baseTop
   local footY, availH
   if scrollMax > 0 then
     availH = minPanelHeight(m)

src/import/RomImporter.lua

@@ -316,18 +316,6 @@ function RomImporter.isReady(version)
 end
 
 -- Load the import manifest for a version and confirm it matches that ROM.
-local function decodeManifest(version)
-  local path = GameVersion.info(version).manifest
-  local raw, readError = love.filesystem.read(path)
-  if not raw then error("ROM import metadata is missing: " .. tostring(readError)) end
-  local Json = require("src.link.Json")
-  local manifest, decodeError = Json.decode(raw)
-  if not manifest then error("ROM import metadata is invalid: " .. tostring(decodeError)) end
-  assert(manifest.romSha1 == GameVersion.info(version).sha1,
-    "ROM import metadata version mismatch")
-  return manifest
-end
-
 local function sha1(data)
   local digest = love.data.hash("sha1", data)
   if type(digest) == "userdata" and digest.getString then
@@ -1552,6 +1540,8 @@ function RomImporter:setError(message, version)
   self.detail = tostring(message)
   self.progress = 0
   self.worker = nil
+  -- Dropping the job stops collection; the next import clears the channels.
+  self._extract = nil
   self.romData = nil
   -- A headless import has no launcher to read this off: POKEPORT_IMPORT_ONLY
   -- only ever quits from onComplete, so an import that fails here would sit in
@@ -1618,23 +1608,65 @@ function RomImporter:startData(data, displayName)
   self.detail = displayName or info.displayName
   self.progress = 0
   self.romData = data
-  self.worker = coroutine.create(function()
-    self.status = "Preparing private game data"
-    coroutine.yield()
-    -- Redirect every cache write to this version's subtree, then clear only
-    -- that version's previous cache from both homes (save directory and, for
-    -- a portable install, the game folder).  The other version is untouched.
-    local CacheFs = require("src.import.CacheFs")
-    local prefix = info.cachePrefix
-    CacheFs.prefix = prefix
+  self.status = "Preparing private game data"
+
+  -- Clear this version's previous cache from both homes before anything
+  -- writes.  Stays on the main thread so delete-then-fill-then-mark keeps one
+  -- owner; the prefix is restored at once because the worker sets its own.
+  local CacheFs = require("src.import.CacheFs")
+  local prefix = info.cachePrefix
+  local savedPrefix = CacheFs.prefix
+  CacheFs.prefix = prefix
+  local cleared, clearError = pcall(function()
     removeTree(prefix .. "data/generated")
     removeTree(prefix .. "assets/generated")
     love.filesystem.remove(prefix .. MARKER_PATH)
     CacheFs.removeTree("data/generated")
     CacheFs.removeTree("assets/generated")
     CacheFs.remove(MARKER_PATH)
+  end)
+  CacheFs.prefix = savedPrefix
+  if not cleared then
+    self:setError(tostring(clearError), version)
+    return
+  end
 
-    local manifest = decodeManifest(version)
+  if self:_startExtractThread(version, prefix, data, displayName) then return end
+  self:_startExtractCoroutine(version, info, prefix, displayName)
+end
+
+-- False when threads are unavailable, so the coroutine path still covers
+-- that host.  POKEPORT_NO_THREAD=1 forces it, which is the only way to
+-- exercise the fallback on a desktop.
+function RomImporter:_startExtractThread(version, prefix, data, displayName)
+  if os.getenv("POKEPORT_NO_THREAD") == "1" then return false end
+  if not (love.thread and love.thread.newThread) then return false end
+  local ok, thread = pcall(love.thread.newThread, "src/import/ExtractThread.lua")
+  if not ok or not thread then return false end
+  local progressName = "rom_import_progress"
+  local resultName = "rom_import_result"
+  love.thread.getChannel(progressName):clear()
+  love.thread.getChannel(resultName):clear()
+  local started = pcall(thread.start, thread, version, prefix, data,
+    progressName, resultName)
+  if not started then return false end
+  self._extract = {
+    thread = thread, version = version, prefix = prefix,
+    displayName = displayName,
+    progress = love.thread.getChannel(progressName),
+    result = love.thread.getChannel(resultName),
+  }
+  -- The worker owns the bytes now; drop ours so the 1-2 MiB string can go.
+  self.romData = nil
+  return true
+end
+
+function RomImporter:_startExtractCoroutine(version, info, prefix, displayName)
+  self.worker = coroutine.create(function()
+    coroutine.yield()
+    local CacheFs = require("src.import.CacheFs")
+    CacheFs.prefix = prefix
+    local manifest = require("src.import.RomManifest").decode(version)
     local RomExtractor = version == "gold"
       and require("src.import.RomExtractorGen2")
       or require("src.import.RomExtractor")
@@ -1647,47 +1679,93 @@ function RomImporter:startData(data, displayName)
         coroutine.yield()
       end)
     extractor:run()
+    CacheFs.prefix = ""   -- restore the default so later writes stay at the root
     self.romData = nil
     collectgarbage("collect")
-    -- Written last: the marker is what isReady() checks, so it must only
-    -- appear once every required file is in place.
-    local ok, writeError = CacheFs.write(MARKER_PATH, markerFor(version))
-    CacheFs.prefix = ""   -- restore the default so later writes stay at the root
-    if not ok then error("could not finish the private cache: " .. tostring(writeError)) end
-    self.ready[version] = true
-    self.returning[version] = false
-    self.romName[version] = (displayName
-      and (displayName:match("[^/\\]+$") or displayName)) or self.romName[version]
-    -- Android: drop the consumed save-dir .gb/.gbc (picked_rom.gb or a USB copy)
-    -- so the next Choose / focus cannot treat it as a fresh pending ROM.
-    if self.mobileFileBridge and type(displayName) == "string"
-        and not displayName:find("[/\\]") then
-      love.filesystem.remove(displayName)
-    end
-    self.importing = nil
-    self.workState = "complete"
-    self.completeVersion = version
-    self.status = "Ready"
-    -- NX launcher stays put: keep the imports/ cleanup hint instead of
-    -- overwriting it with a "Starting…" line that never boots from here.
-    if self.launcher and self.isNX and type(displayName) == "string" then
-      self.detail = Strings("%s imported. You may delete the copy from "
-        .. "imports/ when finished.", displayName)
-    else
-      self.detail = "Starting " .. info.displayName .. "..."
-    end
-    self.progress = 1
-    if self.launcher then
-      -- Stay on the launcher; the player presses Play to boot the new game.
-      return
-    end
-    self._handedOff = true
-    resetPointerCursor(self)
-    if self._flex then require("src.import.LauncherView").detach(self) end
-    if self.onComplete then self.onComplete(version) end
+    self:_completeImport(version, prefix, displayName)
   end)
 end
 
+-- Everything after the tree is filled, shared by both worker paths.  Raises
+-- on a failed marker write; the thread path calls it inside a pcall.
+function RomImporter:_completeImport(version, prefix, displayName)
+  local info = GameVersion.info(version)
+  local CacheFs = require("src.import.CacheFs")
+  -- Written last: the marker is what isReady() checks, so it must only
+  -- appear once every required file is in place.
+  local savedPrefix = CacheFs.prefix
+  CacheFs.prefix = prefix
+  local ok, writeError = CacheFs.write(MARKER_PATH, markerFor(version))
+  CacheFs.prefix = savedPrefix
+  if not ok then
+    error("could not finish the private cache: " .. tostring(writeError))
+  end
+  self.ready[version] = true
+  self.returning[version] = false
+  self.romName[version] = (displayName
+    and (displayName:match("[^/\\]+$") or displayName)) or self.romName[version]
+  -- Android: drop the consumed save-dir .gb/.gbc (picked_rom.gb or a USB copy)
+  -- so the next Choose / focus cannot treat it as a fresh pending ROM.
+  if self.mobileFileBridge and type(displayName) == "string"
+      and not displayName:find("[/\\]") then
+    love.filesystem.remove(displayName)
+  end
+  self.importing = nil
+  self.workState = "complete"
+  self.completeVersion = version
+  self.status = "Ready"
+  -- NX launcher stays put: keep the imports/ cleanup hint instead of
+  -- overwriting it with a "Starting…" line that never boots from here.
+  if self.launcher and self.isNX and type(displayName) == "string" then
+    self.detail = Strings("%s imported. You may delete the copy from "
+      .. "imports/ when finished.", displayName)
+  else
+    self.detail = "Starting " .. info.displayName .. "..."
+  end
+  self.progress = 1
+  if self.launcher then
+    -- Stay on the launcher; the player presses Play to boot the new game.
+    return
+  end
+  self._handedOff = true
+  resetPointerCursor(self)
+  if self._flex then require("src.import.LauncherView").detach(self) end
+  if self.onComplete then self.onComplete(version) end
+end
+
+-- Drain the worker's progress and finish when it reports done.  One
+-- non-blocking poll per frame, like the other _pump* collectors above.
+function RomImporter:_pumpExtract()
+  local job = self._extract
+  if not job then return end
+  local msg = job.progress:pop()
+  while msg do
+    self.status = msg.stage
+    self.progress = msg.progress / msg.total
+    self.stageCurrent = msg.current
+    self.stageTotal = msg.stageTotal
+    msg = job.progress:pop()
+  end
+  local res = job.result:pop()
+  if not res then
+    -- A thread that died before pushing a result would strand the loader.
+    local threadError = job.thread.getError and job.thread:getError()
+    if threadError then
+      self._extract = nil
+      self:setError(tostring(threadError), job.version)
+    end
+    return
+  end
+  self._extract = nil
+  if not res.ok then
+    self:setError(tostring(res.error), job.version)
+    return
+  end
+  local ok, err = pcall(self._completeImport, self, job.version, job.prefix,
+    job.displayName)
+  if not ok then self:setError(tostring(err), job.version) end
+end
+
 function RomImporter:startPath(path)
   if not path then return end
   local data, readError = readExternalPath(path)
@@ -2316,6 +2394,7 @@ function RomImporter:update(dt)
   self:_pumpFindThumbs()
   self:_pumpModCheck()
   self:_pumpModInstall()
+  self:_pumpExtract()
   -- Dev harness: POKEPORT_LAUNCHER_SHOT=/path.png resizes the window from
   -- POKEPORT_WIN=WxH, lets the view settle, then captures one frame and
   -- quits, so a scripted run can see the real launcher at any window shape
@@ -4090,11 +4169,19 @@ end
 
 -- Turn finished thumbnail downloads into images.  Called from update(), so
 -- love.graphics.newImage runs on the render thread where it belongs.
+-- love.graphics.newImage decodes the PNG and uploads it, both on the render
+-- thread.  A page's worth of thumbnails landing in the same frame did that
+-- many times back to back and dropped the frame, so only this many are
+-- decoded per pass; the rest keep their spinner one frame longer.
+local THUMB_DECODES_PER_FRAME = 2
+
 function RomImporter:_pumpFindThumbs()
   local pending = self._findThumbFetch
   if not pending then return end
   local Fetch = require("src.net.Fetch")
+  local decoded = 0
   for id, item in pairs(pending) do
+    if decoded >= THUMB_DECODES_PER_FRAME then break end
     local st = Fetch.poll(item.job)
     if st.status ~= "pending" then
       Fetch.release(item.job)
@@ -4103,6 +4190,7 @@ function RomImporter:_pumpFindThumbs()
       if st.status == "ok" and st.path then
         local ok, img = pcall(love.graphics.newImage, st.path)
         image = ok and img or nil
+        decoded = decoded + 1
       end
       self._findThumbs = self._findThumbs or {}
       self._findThumbs[id] = image or false
@@ -4119,14 +4207,21 @@ end
 -- entry per frame so opening the tab cannot stall for the whole listing.
 -- The result is memoized per id for the session; a repo with no releases
 -- or a failed fetch resolves to an empty table so it is tried once.
-function RomImporter:_findStats(entry)
+-- PURE read: whatever is already known for a row, or nil.  Resolving a
+-- feed-published stat or a repo-less entry is memoization, not network, so it
+-- stays here; nothing in this function can start a fetch.  That matters
+-- because the sort comparator calls it for EVERY entry -- when queueing lived
+-- in here, sorting a 500-mod index by Popularity queued 500 GitHub requests
+-- on the first frame, blew the hourly rate limit, and the failures then
+-- re-queued together every 60s for as long as the tab was open.
+function RomImporter:_findStatsCached(entry)
   self._findStatsCache = self._findStatsCache or {}
   local cached = self._findStatsCache[entry.id]
   if cached then
     if cached.done or (cached.retryAt and os.time() < cached.retryAt) then
       return cached
     end
-    self._findStatsCache[entry.id] = nil  -- retry window open, refetch
+    return nil   -- retry window open; _requestFindStats decides what to do
   end
   if entry.downloads ~= nil or entry.first_release or entry.last_release then
     cached = { total = entry.downloads, first = entry.first_release,
@@ -4139,22 +4234,54 @@ function RomImporter:_findStats(entry)
     self._findStatsCache[entry.id] = cached
     return cached
   end
-  -- ASYNC (was a blocking fetch, one row per frame).  "One per frame" bounded
-  -- how many stalls happened at once, not how long each one lasted: every
-  -- frame that started a fetch blocked for the whole round trip, so scrolling
-  -- a listing juddered once per row.  Rows now queue a handle and fill in
-  -- when it lands; until then the row simply has no stats line.
-  self._findStatsPending = self._findStatsPending or {}
-  if not self._findStatsPending[entry.id] then
-    local ModUpdate = require("src.mods.ModUpdate")
-    self._findStatsPending[entry.id] = {
-      id = entry.id,
-      h = ModUpdate.beginFetchReleases(entry.github, entry.id, {}),
-    }
-  end
   return nil
 end
 
+-- Queue one row's release fetch.  Only rows actually on the page call this --
+-- the rule _findThumb already follows -- so the fan-out is a page, not the
+-- whole index.
+function RomImporter:_requestFindStats(entry)
+  if self:_findStatsCached(entry) then return end
+  if not entry.github or entry.github == "" then return end
+  local cached = self._findStatsCache[entry.id]
+  if cached then
+    if cached.retryAt and os.time() >= cached.retryAt then
+      self._findStatsCache[entry.id] = nil   -- retry window open, refetch
+    else
+      return
+    end
+  end
+  self._findStatsPending = self._findStatsPending or {}
+  if self._findStatsPending[entry.id] then return end
+  local ModUpdate = require("src.mods.ModUpdate")
+  self._findStatsPending[entry.id] = {
+    id = entry.id,
+    h = ModUpdate.beginFetchReleases(entry.github, entry.id, {}),
+  }
+end
+
+-- Request-and-read, for a row that is being drawn and for the detail modal.
+function RomImporter:_findStats(entry)
+  self:_requestFindStats(entry)
+  return self:_findStatsCached(entry)
+end
+
+-- How many rows are still waiting on a release check, for the panel's
+-- progress line.
+function RomImporter:_findStatsPendingCount()
+  local n = 0
+  for _ in pairs(self._findStatsPending or {}) do n = n + 1 end
+  return n
+end
+
+function RomImporter:_findStatsPendingFor(id)
+  return (self._findStatsPending and self._findStatsPending[id]) ~= nil
+end
+
+function RomImporter:_findThumbPending(id)
+  return (self._findThumbFetch and self._findThumbFetch[id]) ~= nil
+end
+
 -- Drive in-flight FIND MODS stats lookups.  Called from update().
 function RomImporter:_pumpFindStats()
   local pending = self._findStatsPending

src/import/RomManifest.lua

@@ -0,0 +1,25 @@
+-- The per-version import metadata (symbol table + ROM hash) that drives
+-- RomExtractor.  Split out of RomImporter so the extraction worker thread can
+-- decode it itself: shipping the decoded table across a love.thread channel
+-- would deep-copy every symbol for nothing.
+
+local GameVersion = require("src.core.GameVersion")
+
+local RomManifest = {}
+
+function RomManifest.decode(version)
+  local info = GameVersion.info(version)
+  local raw, readError = love.filesystem.read(info.manifest)
+  if not raw then
+    error("ROM import metadata is missing: " .. tostring(readError))
+  end
+  local Json = require("src.link.Json")
+  local manifest, decodeError = Json.decode(raw)
+  if not manifest then
+    error("ROM import metadata is invalid: " .. tostring(decodeError))
+  end
+  assert(manifest.romSha1 == info.sha1, "ROM import metadata version mismatch")
+  return manifest
+end
+
+return RomManifest

src/mods/Job.lua

@@ -0,0 +1,209 @@
+-- Background compute for sandboxed mods, behind the "background" permission.
+--
+-- mod.fetch covers work that is waiting on a server.  This covers work that is
+-- waiting on the CPU: a mod hands over a script from its own folder plus a
+-- table of plain data, and gets the return value back through the same
+-- handle/poll/release shape mod.fetch uses.
+--
+-- The worker (src/mods/job_worker.lua) builds the SAME Sandbox.envFor
+-- environment the main thread does before it loads the mod's chunk, so this
+-- is not the love.thread hole reopened: the mod's code still cannot see
+-- io, os, debug, ffi, package or love.filesystem, and require is refused
+-- outright inside a job.
+--
+-- One thread per job rather than a pool.  A pooled state would carry one
+-- mod's globals into the next mod's job, and resetting it properly is the
+-- same work as making a new one.
+
+local SafePath = require("src.mods.SafePath")
+
+local Job = {}
+
+Job.MAX_INFLIGHT = 2       -- per mod
+Job.MAX_GLOBAL = 4         -- across all mods, so jobs cannot eat every core
+Job.DEFAULT_SECONDS = 5
+Job.MAX_SECONDS = 30
+-- Depth cap on the data crossing the channel.  A cycle is caught by the seen
+-- set; this catches the merely absurd.
+Job.MAX_DEPTH = 16
+
+local nextId = 0
+local liveGlobal = 0
+
+-- Only plain data crosses a thread boundary: a function or userdata cannot be
+-- serialised, and letting one through would fail deep inside LÖVE instead of
+-- at the call the mod made.
+local function plain(value, depth, seen)
+  local t = type(value)
+  if t == "nil" or t == "boolean" or t == "number" or t == "string" then
+    return value
+  end
+  if t ~= "table" then
+    return nil, ("a job cannot carry a %s, only plain data"):format(t)
+  end
+  depth = (depth or 0) + 1
+  if depth > Job.MAX_DEPTH then
+    return nil, "a job's data is nested too deeply"
+  end
+  seen = seen or {}
+  if seen[value] then return nil, "a job cannot carry a cycle" end
+  seen[value] = true
+  local out = {}
+  for k, v in pairs(value) do
+    local kt = type(k)
+    if kt ~= "string" and kt ~= "number" then
+      return nil, ("a job cannot carry a %s key"):format(kt)
+    end
+    local copied, err = plain(v, depth, seen)
+    if err then return nil, err end
+    out[k] = copied
+  end
+  seen[value] = nil
+  return out
+end
+Job.plain = plain
+
+function Job.available()
+  return (love and love.thread and love.thread.newThread) ~= nil
+end
+
+local function bucket(loader, modId)
+  loader.jobs = loader.jobs or {}
+  local b = loader.jobs[modId]
+  if not b then b = {}; loader.jobs[modId] = b end
+  return b
+end
+
+local function inflight(b)
+  local n = 0
+  for _, job in pairs(b) do
+    if job.status == "pending" then n = n + 1 end
+  end
+  return n
+end
+
+-- `script` is relative to the mod's own folder, and goes through the same
+-- SafePath rules mod:read does -- a job is not a way to name a path.
+-- Argument checks come BEFORE the host check: a bad path or an unserialisable
+-- argument is the mod author's bug and should read the same on every machine,
+-- not be masked into "unavailable" on a build without threads.
+function Job.run(loader, modId, modPath, script, arg, opts)
+  if type(script) ~= "string" or script == "" then
+    return nil, "a job needs a script path inside your mod"
+  end
+  -- SafePath.require raises rather than returning, so the mod's bad path
+  -- comes back as a value here instead of unwinding its caller.
+  local okPath, safe = pcall(SafePath.join, modPath, script, "a job script")
+  if not okPath then return nil, tostring(safe) end
+  local payload, dataErr = plain(arg)
+  if dataErr then return nil, dataErr end
+  if not Job.available() then return nil, "background jobs are unavailable" end
+
+  local b = bucket(loader, modId)
+  if inflight(b) >= Job.MAX_INFLIGHT then
+    return nil, ("too many jobs in flight (limit %d); poll and release the "
+      .. "ones you have"):format(Job.MAX_INFLIGHT)
+  end
+  if liveGlobal >= Job.MAX_GLOBAL then
+    return nil, "the machine is already running as many jobs as it will"
+  end
+
+  opts = type(opts) == "table" and opts or {}
+  local seconds = tonumber(opts.maxSeconds) or Job.DEFAULT_SECONDS
+  if seconds > Job.MAX_SECONDS then seconds = Job.MAX_SECONDS end
+  if seconds < 1 then seconds = 1 end
+
+  nextId = nextId + 1
+  local argName = "modjob_arg_" .. nextId
+  local resultName = "modjob_result_" .. nextId
+  local argCh = love.thread.getChannel(argName)
+  local resCh = love.thread.getChannel(resultName)
+  argCh:clear()
+  resCh:clear()
+  argCh:push(payload == nil and false or payload)
+
+  local okNew, thread = pcall(love.thread.newThread, "src/mods/job_worker.lua")
+  if not okNew or not thread then return nil, "could not start a job thread" end
+  local Json = require("src.link.Json")
+  local permissions = select(2, pcall(Json.encode,
+    loader.mods and loader.mods[modId]
+      and loader.mods[modId].manifest.permissionSet or {})) or "{}"
+  local started = pcall(thread.start, thread, modId, safe, argName, resultName,
+    permissions)
+  if not started then return nil, "could not start a job thread" end
+
+  liveGlobal = liveGlobal + 1
+  local handle = {}
+  b[handle] = { thread = thread, resultCh = resCh, status = "pending",
+                deadline = love.timer.getTime() + seconds, seconds = seconds }
+  return handle
+end
+
+local function settle(job, status, value, err)
+  if job.status == "pending" then liveGlobal = math.max(0, liveGlobal - 1) end
+  job.status, job.value, job.err = status, value, err
+end
+
+function Job.poll(loader, modId, handle)
+  local job = bucket(loader, modId)[handle]
+  if not job then return { status = "error", err = "unknown job" } end
+  if job.status == "pending" then
+    local msg = job.resultCh:pop()
+    if msg then
+      if msg.ok then settle(job, "ok", msg.result)
+      else settle(job, "error", nil, msg.err) end
+    else
+      -- A worker that died before pushing anything (an error outside its own
+      -- pcall) would otherwise leave the mod polling forever.
+      local threadErr = job.thread.getError and job.thread:getError()
+      if threadErr then
+        settle(job, "error", nil, tostring(threadErr))
+      elseif love.timer.getTime() > job.deadline then
+        -- The budget bounds how long the MOD waits, not how long the work
+        -- runs: there is no way to stop a LÖVE thread, and every in-worker
+        -- attempt made things worse (see job_worker.lua).  A job that
+        -- overruns is reported here and its result dropped if it ever lands.
+        settle(job, "error", nil, ("job exceeded its %gs budget")
+          :format(job.seconds))
+      end
+    end
+  end
+  if job.status == "ok" then
+    -- A copy, so a mod cannot edit what a later poll returns.
+    return { status = "ok", result = (plain(job.value)) }
+  end
+  return { status = job.status, err = job.err }
+end
+
+function Job.release(loader, modId, handle)
+  local b = bucket(loader, modId)
+  local job = b[handle]
+  if not job then return false end
+  if job.status == "pending" then liveGlobal = math.max(0, liveGlobal - 1) end
+  b[handle] = nil
+  return true
+end
+
+-- There is no way to kill a LÖVE thread, so cancelling drops the result
+-- rather than stopping the work; the worker's own time budget is what bounds
+-- how long an abandoned job can run.
+function Job.cancel(loader, modId, handle)
+  local job = bucket(loader, modId)[handle]
+  if not job then return false end
+  if job.status == "pending" then
+    settle(job, "cancelled")
+  end
+  return true
+end
+
+function Job.releaseAll(loader, modId)
+  local b = loader.jobs and loader.jobs[modId]
+  if not b then return end
+  for handle, job in pairs(b) do
+    if job.status == "pending" then liveGlobal = math.max(0, liveGlobal - 1) end
+    b[handle] = nil
+  end
+  loader.jobs[modId] = nil
+end
+
+return Job

src/mods/LegacyCompat.lua

@@ -662,7 +662,13 @@ end
 
 local function systemShim(ctx)
   local function real() return _G.love and _G.love.system or nil end
-  return {
+  -- tls* comes from the engine (Android JNI, or desktop gen1tls hung on
+  -- love.system at boot).  Forward those; keep clipboard / openURL stubbed.
+  local TLS = {
+    tlsOpen = true, tlsStatus = true, tlsSend = true,
+    tlsReceive = true, tlsError = true, tlsClose = true,
+  }
+  local shim = {
     getOS = function()
       local sys = real()
       return sys and sys.getOS and sys.getOS() or "Unknown"
@@ -697,6 +703,13 @@ local function systemShim(ctx)
       return false
     end,
   }
+  return setmetatable(shim, {
+    __index = function(_, key)
+      if not TLS[key] then return nil end
+      local sys = real()
+      return sys and sys[key]
+    end,
+  })
 end
 
 local function eventShim(ctx)

src/mods/Loader.lua

@@ -23,6 +23,8 @@ local Hooks = require("src.mods.Hooks")
 local LegacyCompat = require("src.mods.LegacyCompat")
 local Runtime = require("src.mods.Runtime")
 local Steps = require("src.mods.Steps")
+local Net = require("src.mods.Net")
+local Job = require("src.mods.Job")
 
 local Loader = {}
 Loader.__index = Loader
@@ -1070,6 +1072,51 @@ function Loader:_api(mod)
       return { available = function() return false end,
                sync = refuse, poll = refuse }
     end)(),
+    -- Background HTTP, behind the "network" permission the player already
+    -- sees.  This is what love.thread is NOT: the worker runs engine code in
+    -- an engine-owned pool, so a mod gets asynchrony without getting a Lua
+    -- state the sandbox cannot reach.  get() hands back an opaque handle;
+    -- poll() is non-blocking, so nothing here can hang a frame.
+    fetch = (function()
+      if mod.manifest.permissionSet.network then
+        return {
+          available = function() return Net.available() end,
+          get = function(_, url, opts) return Net.get(loader, modId, url, opts) end,
+          poll = function(_, handle) return Net.poll(loader, modId, handle) end,
+          release = function(_, handle) return Net.release(loader, modId, handle) end,
+          cancel = function(_, handle) return Net.cancel(loader, modId, handle) end,
+        }
+      end
+      local function refuse()
+        error(('[%s] mod.fetch needs the "network" permission in '
+          .. "manifest.json"):format(modId), 2)
+      end
+      return { available = function() return false end,
+               get = refuse, poll = refuse, release = refuse, cancel = refuse }
+    end)(),
+    -- Background compute, behind the "background" permission.  The worker
+    -- rebuilds this mod's sandbox before loading the script, so a job is the
+    -- one thing love.thread is not: off the main thread without a Lua state
+    -- that escapes the sandbox.  Plain data in, plain data out.
+    job = (function()
+      if mod.manifest.permissionSet.background then
+        return {
+          available = function() return Job.available() end,
+          run = function(_, script, arg, opts)
+            return Job.run(loader, modId, mod.path, script, arg, opts)
+          end,
+          poll = function(_, handle) return Job.poll(loader, modId, handle) end,
+          release = function(_, handle) return Job.release(loader, modId, handle) end,
+          cancel = function(_, handle) return Job.cancel(loader, modId, handle) end,
+        }
+      end
+      local function refuse()
+        error(('[%s] mod.job needs the "background" permission in '
+          .. "manifest.json"):format(modId), 2)
+      end
+      return { available = function() return false end,
+               run = refuse, poll = refuse, release = refuse, cancel = refuse }
+    end)(),
     -- namespaced per mod; M11 backs these with save.modData /
     -- options.modOptions, the shape mods compile against is already final
     save = {
@@ -1342,6 +1389,8 @@ function Loader:_rollback(modId)
   self.migrations[modId] = nil
   self.modSave[modId] = nil
   self.stepsQueues[modId] = nil
+  Net.releaseAll(self, modId)
+  Job.releaseAll(self, modId)
 end
 
 -- a mod that explicitly swears it stays link-compatible while writing into a

src/mods/Manifest.lua

@@ -11,7 +11,8 @@ local Manifest = {}
 
 Manifest.PROFILES = { content = true, overhaul = true, total_conversion = true }
 Manifest.PERMISSIONS = { network = true, filesystem = true,
-                         engine_internals = true, steps = true }
+                         engine_internals = true, steps = true,
+                         background = true }
 
 -- link-relevant registries; a mod that writes into one of these while
 -- declaring affects_link = false gets an attributed warning from the loader

src/mods/Net.lua

@@ -0,0 +1,143 @@
+-- Background HTTP for sandboxed mods, behind the "network" permission.
+--
+-- The sandbox blocks love.thread because newThread boots a Lua state with a
+-- full standard library that none of the sandbox's rules reach -- one call and
+-- a mod has io back.  That is correct, but it left mods with no way to do
+-- anything off the main thread at all: the only reachable transports
+-- (socket, http) block, so a mod that wanted to fetch something had to hang
+-- the game to do it.
+--
+-- This is the narrow replacement.  src/net/Fetch.lua already runs a pool of
+-- engine-owned worker threads, and those workers run OUR code, not the mod's,
+-- so handing a mod a job in that pool grants no new reach.  A mod submits a
+-- URL and polls for the body; it never gets a thread, a path, or a raw handle
+-- into the shared job table.
+--
+-- WHAT THIS FILE HAS TO GET RIGHT, because Fetch itself is shared with the
+-- launcher:
+--   * Handles are opaque tables owned per mod.  Fetch keys jobs by integer,
+--     and the launcher's own ROM download and index fetches live in the same
+--     table; an integer handed to a mod would let it poll (or cancel) work
+--     that is not its own.  A forged table simply misses the lookup.
+--   * Only http and https.  The transport is curl, which also speaks file://,
+--     scp:// and ftp://; without this check mod.fetch would be a filesystem
+--     read and the sandbox would be back to square one.
+--   * A per-mod ceiling on jobs in flight, so one mod cannot fill the shared
+--     three-worker pool and starve the launcher's own fetches.
+
+local Net = {}
+
+-- Per mod, not global: the pool is shared with the launcher and a mod should
+-- never be able to monopolise it.
+Net.MAX_INFLIGHT = 4
+-- Clamp on the caller's timeout, so a mod cannot pin a worker indefinitely.
+Net.MAX_SECONDS = 30
+
+local function fetch()
+  return require("src.net.Fetch")
+end
+
+-- http/https only, and a host must actually be present -- "http://" alone
+-- reaches curl as a malformed URL rather than being refused here.
+function Net.urlDenial(url)
+  if type(url) ~= "string" or url == "" then return "url must be a string" end
+  local scheme, rest = url:match("^(%a[%w+.-]*)://(.*)$")
+  if not scheme then return "url must start with http:// or https://" end
+  scheme = scheme:lower()
+  if scheme ~= "http" and scheme ~= "https" then
+    return ("%s:// is not allowed; mod.fetch speaks http and https only")
+      :format(scheme)
+  end
+  if rest == "" or rest:match("^/") then return "url has no host" end
+  return nil
+end
+
+local function bucket(loader, modId)
+  loader.netJobs = loader.netJobs or {}
+  local b = loader.netJobs[modId]
+  if not b then b = {}; loader.netJobs[modId] = b end
+  return b
+end
+
+local function inflight(b)
+  local n = 0
+  for _, id in pairs(b) do
+    if fetch().isPending(id) then n = n + 1 end
+  end
+  return n
+end
+
+function Net.available()
+  local ok, F = pcall(fetch)
+  if not ok then return false end
+  local okAvail, avail = pcall(F.available)
+  return okAvail and avail and true or false
+end
+
+-- Returns an opaque handle, or nil plus a reason.
+function Net.get(loader, modId, url, opts)
+  local denial = Net.urlDenial(url)
+  if denial then return nil, denial end
+  opts = type(opts) == "table" and opts or {}
+  local b = bucket(loader, modId)
+  if inflight(b) >= Net.MAX_INFLIGHT then
+    return nil, ("too many requests in flight (limit %d); poll and release "
+      .. "the ones you have"):format(Net.MAX_INFLIGHT)
+  end
+  local maxSeconds = tonumber(opts.maxSeconds) or Net.MAX_SECONDS
+  if maxSeconds > Net.MAX_SECONDS then maxSeconds = Net.MAX_SECONDS end
+  if maxSeconds < 1 then maxSeconds = 1 end
+  -- The mod is named in the agent string so a server operator can see which
+  -- mod is calling them, and a mod cannot pretend to be the launcher.
+  local id = fetch().get(url, {
+    userAgent = "gen1recomp-mod/" .. tostring(modId),
+    accept = type(opts.accept) == "string" and opts.accept or nil,
+    maxSeconds = maxSeconds,
+  })
+  local handle = {}
+  b[handle] = id
+  return handle
+end
+
+-- A copy of the job's state, never the engine's own table.  An unknown or
+-- forged handle reads as an error rather than nil, so a mod that lost track of
+-- one cannot spin waiting on it forever.
+function Net.poll(loader, modId, handle)
+  local id = bucket(loader, modId)[handle]
+  if not id then return { status = "error", err = "unknown request" } end
+  local st = fetch().poll(id)
+  return { status = st.status, body = st.body, err = st.err,
+           progress = st.progress }
+end
+
+function Net.release(loader, modId, handle)
+  local b = bucket(loader, modId)
+  local id = b[handle]
+  if not id then return false end
+  fetch().release(id)
+  b[handle] = nil
+  return true
+end
+
+function Net.cancel(loader, modId, handle)
+  local id = bucket(loader, modId)[handle]
+  if not id then return false end
+  fetch().cancel(id)
+  return true
+end
+
+-- Drop everything this mod still holds.  Called when a mod unloads, so a
+-- disabled mod cannot leave jobs accumulating in the shared table.
+function Net.releaseAll(loader, modId)
+  local b = loader.netJobs and loader.netJobs[modId]
+  if not b then return end
+  local F = fetch()
+  for handle, id in pairs(b) do
+    pcall(F.cancel, id)
+    pcall(F.release, id)
+    b[handle] = nil
+  end
+  loader.netJobs[modId] = nil
+end
+
+return Net

src/mods/Sandbox.lua

@@ -68,7 +68,11 @@ end
 -- without an edit here.
 -- value is the replacement to name in the error, or true when there is none
 local BLOCKED_LOVE = {
-  filesystem = "mod.storage, mod:read and mod:list", thread = true,
+  filesystem = "mod.storage, mod:read and mod:list",
+  -- newThread's state has a full standard library and none of this file's
+  -- rules, so it stays blocked -- but the reason mods reached for it was
+  -- background work, and mod.fetch is that without the escape.
+  thread = 'mod.fetch for background HTTP (needs the "network" permission)',
   system = "mod.device:powerInfo() for battery information, mod.steps for "
     .. "the step bridge", event = true,
 }

src/mods/job_worker.lua

@@ -0,0 +1,73 @@
+-- Worker state behind src/mods/Job.lua.  One per job, not a pool: a reused
+-- state would carry one mod's globals into another mod's job.
+--
+-- This is the file that makes running mod Lua off the main thread safe.  The
+-- mod's chunk is loaded into the SAME sandbox environment the main thread
+-- builds (Sandbox.envFor), so love.filesystem, io, os, debug, ffi and package
+-- are as absent here as they are there -- even though this state required
+-- love.filesystem to bootstrap itself.
+--
+-- A job is pure compute: plain data in, plain data out, no engine API, no
+-- game state, no storage.  require is refused outright rather than reaching
+-- src.* -- an engine module loaded in a second state would be a second
+-- instance writing the same files as the main thread's.
+
+require("love.thread")
+require("love.filesystem")
+require("love.timer")
+
+local modId, scriptPath, argChannel, resultChannel, permissionsJson = ...
+
+-- Fresh love threads have no "src.*" searcher (see src/net/fetch_worker.lua),
+-- so install one before Sandbox's own requires run.
+table.insert(package.loaders or package.searchers, function(name)
+  local path = name:gsub("%.", "/") .. ".lua"
+  if not love.filesystem.getInfo(path) then return nil end
+  return love.filesystem.load(path)
+end)
+
+local resCh = love.thread.getChannel(resultChannel)
+
+local function fail(err)
+  resCh:push({ ok = false, err = tostring(err) })
+end
+
+local ok, err = pcall(function()
+  local Sandbox = require("src.mods.Sandbox")
+  local Json = require("src.link.Json")
+
+  local permissions = {}
+  if type(permissionsJson) == "string" and permissionsJson ~= "" then
+    local decoded = select(2, pcall(Json.decode, permissionsJson))
+    if type(decoded) == "table" then permissions = decoded end
+  end
+
+  local env = Sandbox.envFor({ modId = modId, permissions = permissions })
+  -- A job cannot reach the engine.  Anything it needs comes in through its
+  -- argument and goes back through its return value.
+  env.require = function(name)
+    error(("[%s] require(%q) is not available inside a background job; a job "
+      .. "takes plain data and returns plain data"):format(modId,
+      tostring(name)), 2)
+  end
+
+  local chunk, loadErr = Sandbox.loadFile(love.filesystem, scriptPath, env)
+  if not chunk then error(loadErr or ("could not load " .. scriptPath), 0) end
+
+  local arg = love.thread.getChannel(argChannel):pop()
+
+  -- NO in-worker time budget, deliberately.  A debug count hook was the
+  -- obvious way to stop a runaway, and it does not work: LuaJIT swallows an
+  -- error raised from a hook (measured: ~5000 raises a second, the loop
+  -- running straight through them), and the raising itself wedged the whole
+  -- process -- the main thread stopped being scheduled at all.  Without the
+  -- hook a runaway job simply spins on its own core, the game stays
+  -- responsive, and it quits normally.  Job.poll enforces maxSeconds on the
+  -- main thread so the MOD is never left waiting; the work itself runs to its
+  -- own end.
+  local ranOk, result = pcall(chunk, arg)
+  if not ranOk then error(result, 0) end
+  resCh:push({ ok = true, result = result })
+end)
+
+if not ok then fail(err) end

src/net/Gen1Tls.lua

@@ -0,0 +1,100 @@
+-- Load gen1tls from next to the exe and put its poll API on love.system --
+-- same tlsOpen / tlsSend / ... shape Android already exposes through JNI.
+--
+-- Mods can't require("ffi") under the sandbox, so they can't load the DLL
+-- themselves even when it's sitting right there.  We do it here, before any
+-- mod runs.  LegacyCompat's love.system shim forwards the tls* keys through
+-- (clipboard / openURL stay stubbed).
+--
+-- true = tlsOpen is ready.  Already present (Android), no FFI, or no DLL:
+-- just return false and move on; plain ws:// rooms don't care.
+
+local Gen1Tls = {}
+
+local function exeDir()
+  if love and love.filesystem and love.filesystem.getSourceBaseDirectory then
+    local base = love.filesystem.getSourceBaseDirectory()
+    if type(base) == "string" and base ~= "" then return base end
+  end
+  if type(arg) == "table" and type(arg[0]) == "string" then
+    local dir = arg[0]:match("^(.*)[/\\]")
+    if dir and dir ~= "" then return dir end
+  end
+  return "."
+end
+
+local function fileReadable(path)
+  local f = io.open(path, "rb")
+  if not f then return false end
+  f:close()
+  return true
+end
+
+local function libNames()
+  local osName = (love and love.system and love.system.getOS and love.system.getOS()) or ""
+  if osName == "Windows" then return { "gen1tls.dll" } end
+  if osName == "OS X" then return { "libgen1tls.dylib", "gen1tls.dylib" } end
+  if osName == "Linux" then return { "libgen1tls.so", "gen1tls.so" } end
+  return { "gen1tls.dll", "libgen1tls.so", "libgen1tls.dylib" }
+end
+
+function Gen1Tls.install()
+  if not (love and love.system) then return false end
+  if type(love.system.tlsOpen) == "function" then return true end
+
+  local okFfi, ffi = pcall(require, "ffi")
+  if not okFfi or type(ffi) ~= "table" then return false end
+
+  ffi.cdef[[
+    int gen1tls_open(const char *host, int port);
+    int gen1tls_status(int handle);
+    int gen1tls_send(int handle, const char *data, int length);
+    int gen1tls_receive(int handle, char *buf, int max);
+    int gen1tls_error(int handle, char *buf, int max);
+    void gen1tls_close(int handle);
+  ]]
+
+  local dir = exeDir()
+  local lib
+  for _, name in ipairs(libNames()) do
+    local path = dir .. "/" .. name
+    if fileReadable(path) then
+      local ok, loaded = pcall(ffi.load, path)
+      if ok then lib = loaded; break end
+    end
+    local ok, loaded = pcall(ffi.load, name)
+    if ok then lib = loaded; break end
+  end
+  if not lib then return false end
+
+  local errBuf = ffi.new("char[512]")
+  local recvBuf = ffi.new("char[65536]")
+
+  love.system.tlsOpen = function(host, port)
+    return lib.gen1tls_open(host, tonumber(port) or 0)
+  end
+  love.system.tlsStatus = function(handle)
+    return lib.gen1tls_status(handle)
+  end
+  love.system.tlsSend = function(handle, data)
+    data = data or ""
+    return lib.gen1tls_send(handle, data, #data)
+  end
+  love.system.tlsReceive = function(handle, max)
+    max = math.min(tonumber(max) or 8192, 65536)
+    if max <= 0 then return "" end
+    local n = lib.gen1tls_receive(handle, recvBuf, max)
+    if n <= 0 then return "" end
+    return ffi.string(recvBuf, n)
+  end
+  love.system.tlsError = function(handle)
+    if lib.gen1tls_error(handle, errBuf, 512) == 0 then return nil end
+    return ffi.string(errBuf)
+  end
+  love.system.tlsClose = function(handle)
+    lib.gen1tls_close(handle)
+  end
+  return true
+end
+
+return Gen1Tls

src/ui/kit/Kit.lua

@@ -132,9 +132,11 @@ local UI_SCALE = 1.3
 
 function Kit.layout(width, height)
   local s = Theme.clamp(math.min(width / 640, height / 768), 0.9, 1.6) * UI_SCALE
-  local key = ("%dx%d"):format(math.floor(width), math.floor(height))
-  if Kit._fontKey ~= key then
-    Kit._fontKey = key
+  -- Two numbers, not a formatted key: this runs once per frame and the
+  -- string:format allocated on every one of them.
+  local kw, kh = math.floor(width), math.floor(height)
+  if Kit._fontW ~= kw or Kit._fontH ~= kh then
+    Kit._fontW, Kit._fontH = kw, kh
     Kit.fonts = Theme.fonts(s)
     clearCaches()   -- every cached Text/width belongs to the old font set
   end
@@ -857,6 +859,8 @@ end
 -- never silently truncated.  This is the ONLY way the launcher moves through
 -- a long list: no scrollbars, no momentum, bounded row count per frame.
 -- Returns the new page (1-based) and the row height consumed.
+local pagerLabels = {}
+
 function Kit.pager(x, y, w, page, total, perPage, idPrefix)
   local h = math.max(Kit.tapMin(), 30 * Kit.scale)
   local bw = 74 * Kit.scale
@@ -876,7 +880,19 @@ function Kit.pager(x, y, w, page, total, perPage, idPrefix)
 
   local first = total > 0 and ((page - 1) * perPage + 1) or 0
   local last = math.min(total, page * perPage)
-  local label = ("%d-%d of %d   (page %d/%d)"):format(first, last, total, page, pages)
+  -- One memo per pager id.  The counts only change when the user pages or the
+  -- list does; formatting them every frame minted a new string that then
+  -- missed the width / ellipsis / Text caches by content.
+  local memo = pagerLabels[idPrefix]
+  if not memo then memo = {}; pagerLabels[idPrefix] = memo end
+  if memo.first ~= first or memo.last ~= last or memo.total ~= total
+      or memo.page ~= page or memo.pages ~= pages then
+    memo.first, memo.last, memo.total = first, last, total
+    memo.page, memo.pages = page, pages
+    memo.label = ("%d-%d of %d   (page %d/%d)")
+      :format(first, last, total, page, pages)
+  end
+  local label = memo.label
   local labelX = x + 2 * bw + 2 * gap + gap
   Kit.text("mono", Kit.ellipsize("mono", label, math.max(0, x + w - labelX)),
     labelX, y + (h - Kit.textHeight("mono")) / 2, PAL.caption)
@@ -942,7 +958,10 @@ end
 -- region can never unclip its parent.  The tracked rect also bounds Kit.hit,
 -- so a widget clipped out of view is inert instead of taking taps aimed at
 -- whatever is drawn where it left.
+-- The stack rects are pooled by depth and fully overwritten on every push,
+-- so a frame that clips a dozen lists allocates nothing.
 local clipStack = {}
+local clipPool = {}
 
 local function applyClip(rect)
   Kit._clipRect = rect
@@ -967,8 +986,12 @@ function Kit.pushClip(x, y, w, h)
     x2 = math.min(x2, prev.x + prev.w)
     y2 = math.min(y2, prev.y + prev.h)
   end
-  local rect = { x = x, y = y, w = math.max(0, x2 - x), h = math.max(0, y2 - y) }
-  clipStack[#clipStack + 1] = rect
+  local n = #clipStack + 1
+  local rect = clipPool[n]
+  if not rect then rect = {}; clipPool[n] = rect end
+  rect.x, rect.y = x, y
+  rect.w, rect.h = math.max(0, x2 - x), math.max(0, y2 - y)
+  clipStack[n] = rect
   applyClip(rect)
 end
 

src/ui/kit/Layout.lua

@@ -29,6 +29,15 @@ Layout.BP = {
 
 -- Build the frame's metrics.  `maxAppW` caps the content column on an
 -- ultrawide monitor so the UI stays a readable measure instead of stretching.
+-- One metrics table, reused.  Every field is a pure function of the window
+-- size, the safe area and maxAppW, so the table only has to be rebuilt when
+-- one of those changes; the launcher asked for a fresh one 60 times a second
+-- and threw all of them away.  Callers must treat `m` as read-only (nothing
+-- writes to it today) -- a caller that needs a shifted field should save,
+-- assign and restore it around the call, not wrap `m` in a proxy.
+local M = {}
+local lastW, lastH, lastOx, lastOy, lastSw, lastSh, lastMax
+
 function Layout.metrics(maxAppW)
   local W, H = 0, 0
   if love and love.graphics and love.graphics.getDimensions then
@@ -36,23 +45,28 @@ function Layout.metrics(maxAppW)
   end
   local ox, oy, sw, sh = SafeArea.rect()
   local s = Kit.layout(sw, sh)
+  if W == lastW and H == lastH and ox == lastOx and oy == lastOy
+      and sw == lastSw and sh == lastSh and maxAppW == lastMax then
+    return M
+  end
+  lastW, lastH, lastOx, lastOy = W, H, ox, oy
+  lastSw, lastSh, lastMax = sw, sh, maxAppW
 
   local appW = math.min(sw, (maxAppW or 1200) * s)
-  local m = {
-    W = W, H = H, s = s,
-    x = math.floor(ox + (sw - appW) / 2),
-    top = math.floor(oy),
-    w = math.floor(appW),
-    h = math.floor(sh),
-    pad = math.floor(Theme.clamp(appW * 0.03, 10, 24)),
-    gap = math.floor(12 * s),
-    colGap = math.floor(16 * s),
-    rowH = math.max(Kit.tapMin(), math.floor(44 * s)),
-    btnH = math.max(Kit.tapMin(), math.floor(38 * s)),
-    chip = math.max(Kit.tapMin(), math.floor(40 * s)),
-    railH = math.max(3, math.floor(4 * s)),
-    logoH = math.floor(Theme.clamp(sh * 0.10, 36, 84)),
-  }
+  local m = M
+  m.W, m.H, m.s = W, H, s
+  m.x = math.floor(ox + (sw - appW) / 2)
+  m.top = math.floor(oy)
+  m.w = math.floor(appW)
+  m.h = math.floor(sh)
+  m.pad = math.floor(Theme.clamp(appW * 0.03, 10, 24))
+  m.gap = math.floor(12 * s)
+  m.colGap = math.floor(16 * s)
+  m.rowH = math.max(Kit.tapMin(), math.floor(44 * s))
+  m.btnH = math.max(Kit.tapMin(), math.floor(38 * s))
+  m.chip = math.max(Kit.tapMin(), math.floor(40 * s))
+  m.railH = math.max(3, math.floor(4 * s))
+  m.logoH = math.floor(Theme.clamp(sh * 0.10, 36, 84))
   m.cols = (appW >= Layout.BP.threeCol * s and 3)
         or (appW >= Layout.BP.twoCol * s and 2)
         or 1

src/update/Check.lua

@@ -8,9 +8,9 @@
 --   "update_check_state" worker -> main: { status, latest, progress, error }
 --
 -- Nothing here ever blocks or throws into the game loop: when love.thread is
--- absent (the headless test stub) or the worker cannot run (no curl, Android),
--- state() simply reports "error" and the UI hides itself.  See the shared
--- contract in the task brief for the status vocabulary and the file layout.
+-- absent (the headless test stub) or the worker cannot run, state() reports
+-- "error" (or the worker reports "needs_full" when there is no transport).
+-- See the shared contract in the task brief for the status vocabulary.
 --
 -- The release-JSON extraction and the sums parsing are exported as pure
 -- functions (no love.* calls) so plain-Lua tests can cover them, and so the

src/update/check_worker.lua

@@ -5,11 +5,10 @@
 --   "update_check_cmd"   in:  { cmd = "check" | "download" | "quit" }
 --   "update_check_state" out: { status, latest, progress, error }
 --
--- Transport is curl shelled out via io.popen (curl ships on macOS, Windows 10+
--- and desktop Linux).  Everything is wrapped so a missing curl, an HTTP error,
--- or a hung download degrades to a "error"/"needs_full" state rather than
--- blocking or crashing the game.  On Android curl is absent and the check
--- soft-fails to "error", which the UI hides.
+-- Transport is HostShell: curl via io.popen on desktop, the JNI
+-- love.system.httpDownload bridge on Android (same path the mod catalog
+-- already uses).  A missing transport, an HTTP error, or a hung download
+-- degrades to "error"/"needs_full" rather than blocking or crashing the game.
 --
 -- Fresh love threads do not carry the "src.*" package searcher, so sibling
 -- modules are pulled in with love.filesystem.load exactly like
@@ -63,9 +62,12 @@ local API_URL = "https://api.github.com/repos/bryanthaboi/gen1recomp/releases/la
 local pending = nil
 
 -- ---------------------------------------------------------------------------
--- shell / curl
+-- shell / fetch
 -- ---------------------------------------------------------------------------
 
+local UA = "gen1recomp-updater"
+local GH_ACCEPT = "application/vnd.github+json"
+
 local function shq(s)
   s = tostring(s)
   if isWindows then
@@ -74,31 +76,17 @@ local function shq(s)
   return "'" .. s:gsub("'", "'\\''") .. "'"
 end
 
--- run curl and return its response body (text), or nil on any failure.  Used
--- for the small text resources (release JSON, sums file); -f makes curl exit
--- non-zero and emit nothing on an HTTP error, so an empty read is a failure.
-local function curlCapture(url)
-  local cmd = "curl -fsSL --connect-timeout 10 --max-time 40 "
-    .. "-H " .. shq("User-Agent: gen1recomp-updater") .. " "
-    .. "-H " .. shq("Accept: application/vnd.github+json") .. " "
-    .. shq(url)
-  local pipe = HostShell.popen(cmd)
-  if not pipe then return nil end
-  local out = pipe:read("*a")
-  -- HostShell.pclose, not pipe:close(): a close outside the spawn lock can
-  -- free a FILE while another thread's popen walks the stream list, which
-  -- deadlocks that thread permanently (see HostShell's popen notes).
-  HostShell.pclose(pipe)
-  if not out or out == "" then return nil end
-  return out
+-- Small text resources (release JSON, sums file) through HostShell so Android
+-- hits the JNI bridge instead of a curl binary that is never on the device.
+local function fetchText(url, accept)
+  if not HostShell then return nil end
+  local body = HostShell.httpGet(url, UA, accept)
+  if type(body) ~= "string" or body == "" then return nil end
+  return body
 end
 
-local function haveCurl()
-  local pipe = HostShell.popen("curl --version")
-  if not pipe then return false end
-  local out = pipe:read("*a")
-  HostShell.pclose(pipe)
-  return out ~= nil and out:find("curl", 1, true) ~= nil
+local function canFetch()
+  return HostShell and HostShell.canFetch()
 end
 
 -- ---------------------------------------------------------------------------
@@ -170,12 +158,14 @@ end
 local function doCheck()
   post({ status = "checking" })
 
-  if not haveCurl() then
-    post({ status = "error", error = "curl not available" })
+  if not canFetch() then
+    -- No curl and no JNI bridge: the chip becomes "Open releases" so a tap
+    -- still does something instead of retrying a check that cannot succeed.
+    post({ status = "needs_full" })
     return
   end
 
-  local body = curlCapture(API_URL)
+  local body = fetchText(API_URL, GH_ACCEPT)
   if not body then
     post({ status = "error", error = "release check failed" })
     return
@@ -212,7 +202,7 @@ local function doCheck()
   -- pulling the bytes again.
   local finalRel = "updates/" .. rel.payloadName
   if love.filesystem.getInfo(finalRel) then
-    local sums = curlCapture(rel.sums.url)
+    local sums = fetchText(rel.sums.url)
     if sums and verifyPayload(finalRel, rel.payloadName, sums) then
       if gatePasses(finalRel) == false then
         love.filesystem.remove(finalRel)
@@ -279,39 +269,52 @@ local function doDownload()
   local doneAbs = saveDir .. "/updates/" .. rel.payloadName .. ".done"
   local size    = rel.payload.size or 0
 
-  launchDownload(rel.payload.url, partAbs, doneAbs)
+  if HostShell and HostShell.haveCurl() then
+    launchDownload(rel.payload.url, partAbs, doneAbs)
 
-  -- poll the .part size for progress until curl drops the done-marker; a
-  -- stalled or run-away transfer breaks out and lets verification fail cleanly
-  local waited, lastSize, lastChange = 0, -1, 0
-  while true do
-    -- A queued quit means the window already closed.  Bail so the join in
-    -- Check.shutdown does not hold the dead window's process (and, on
-    -- Windows, its folder) open for up to the whole transfer (#727).  The
-    -- quit stays on the channel for the command loop; the detached curl
-    -- times out on its own and the next launch's doCheck verifies and
-    -- re-offers whatever landed.
-    local peeked = cmdCh:peek()
-    if type(peeked) == "table" and peeked.cmd == "quit" then return end
-    if love.filesystem.getInfo(doneRel) then break end
-    local pinfo = love.filesystem.getInfo(partRel)
-    local cur = (pinfo and pinfo.size) or 0
-    if size > 0 then
-      local p = cur / size
-      if p > 0.999 then p = 0.999 end -- 1.0 is reserved for "ready"
-      post({ status = "downloading", latest = rel.version, progress = p })
-    else
-      post({ status = "downloading", latest = rel.version })
+    -- poll the .part size for progress until curl drops the done-marker; a
+    -- stalled or run-away transfer breaks out and lets verification fail cleanly
+    local waited, lastSize, lastChange = 0, -1, 0
+    while true do
+      -- A queued quit means the window already closed.  Bail so the join in
+      -- Check.shutdown does not hold the dead window's process (and, on
+      -- Windows, its folder) open for up to the whole transfer (#727).  The
+      -- quit stays on the channel for the command loop; the detached curl
+      -- times out on its own and the next launch's doCheck verifies and
+      -- re-offers whatever landed.
+      local peeked = cmdCh:peek()
+      if type(peeked) == "table" and peeked.cmd == "quit" then return end
+      if love.filesystem.getInfo(doneRel) then break end
+      local pinfo = love.filesystem.getInfo(partRel)
+      local cur = (pinfo and pinfo.size) or 0
+      if size > 0 then
+        local p = cur / size
+        if p > 0.999 then p = 0.999 end -- 1.0 is reserved for "ready"
+        post({ status = "downloading", latest = rel.version, progress = p })
+      else
+        post({ status = "downloading", latest = rel.version })
+      end
+      if cur ~= lastSize then lastSize, lastChange = cur, waited end
+      if waited - lastChange > 60 then break end -- 60s with no growth: give up
+      if waited > 960 then break end             -- absolute ceiling
+      love.timer.sleep(0.25)
+      waited = waited + 0.25
     end
-    if cur ~= lastSize then lastSize, lastChange = cur, waited end
-    if waited - lastChange > 60 then break end -- 60s with no growth: give up
-    if waited > 960 then break end             -- absolute ceiling
-    love.timer.sleep(0.25)
-    waited = waited + 0.25
+    love.filesystem.remove(doneRel)
+  else
+    -- Android JNI bridge: blocking write, same as fetch_worker.  Progress
+    -- cannot be sampled from inside httpDownload.
+    local ok = HostShell and HostShell.httpDownload(
+      rel.payload.url, partAbs, UA, nil, 900)
+    if not ok then
+      love.filesystem.remove(partRel)
+      post({ status = "error", error = "download failed" })
+      return
+    end
+    post({ status = "downloading", latest = rel.version, progress = 0.999 })
   end
-  love.filesystem.remove(doneRel)
 
-  local sums = curlCapture(rel.sums and rel.sums.url or "")
+  local sums = fetchText(rel.sums and rel.sums.url or "")
   if not sums then
     love.filesystem.remove(partRel)
     post({ status = "error", error = "checksum fetch failed" })

tests/engine/android_host_extension_test.lua

@@ -55,4 +55,24 @@ check(not source:find("QuestActivity", 1, true) and
       not source:find("QuestBridge", 1, true),
   "generic Android activity must not require Quest classes")
 
+-- Required mod files use Android's Storage Access Framework, which works with
+-- Android 13 scoped storage without broad media/storage permissions. Keep the
+-- native destination distinct so it cannot be consumed as a game ROM.
+check(source:find('PICKED_REQUIRED_IMPORT_FILENAME = "picked_required_import.bin"',
+  1, true), "required imports use their own Android picker destination")
+check(source:find("showRequiredImportFilePicker", 1, true),
+  "Android exposes a required-import picker entry point")
+check(source:find("Intent.ACTION_OPEN_DOCUMENT", 1, true)
+    and source:find("Intent.FLAG_GRANT_READ_URI_PERMISSION", 1, true),
+  "Android 13 uses SAF with an explicit read grant")
+
+local systemPath = "mobile/android/love/src/jni/love/src/modules/system/System.cpp"
+local systemFile = assert(io.open(systemPath, "rb"))
+local system = systemFile:read("*a")
+systemFile:close()
+check(system:find('strcmp(kind, "required_import")', 1, true)
+    and system:find('dest = "picked_required_import.bin"', 1, true)
+    and system:find('return "rom,mod,sav,required_import"', 1, true),
+  "native Android bridge advertises and routes required imports")
+
 print("android_host_extension_test: ok")

tests/engine/ios_required_import_picker_test.lua

@@ -0,0 +1,32 @@
+-- iOS required imports travel through the same document-picker contract as
+-- Android. Keep the Swift bridge and liblove patch aligned: a build that has
+-- only one side would show the import button but fail on device.
+local function read(path)
+  local file = assert(io.open(path, "rb"))
+  local data = file:read("*a")
+  file:close()
+  return data
+end
+
+local function check(value, message)
+  if not value then error(message, 2) end
+end
+
+local bridge = read("mobile/ios/native/GRPickerBridge.swift")
+check(bridge:find('case "required_import":', 1, true)
+    and bridge:find('destName = "picked_required_import.bin"', 1, true),
+  "iOS routes required imports to their own staged filename")
+check(bridge:find("types.append(.data)", 1, true)
+    and bridge:find("types.append(.item)", 1, true),
+  "iOS required imports accept user-owned binary ROM files")
+check(bridge:find('"rom,mod,sav,stadium,required_import"', 1, true),
+  "iOS advertises required_import to Lua before opening the picker")
+
+local patch = read("mobile/ios/patch_love_src.py")
+check(patch:find("int w_pickFileKinds", 1, true)
+    and patch:find('{ "pickFileKinds", w_pickFileKinds }', 1, true),
+  "iOS liblove patch exposes the picker capability query")
+check(patch:find('("GRPickerBridge.swift", ID_FILE_PICKER', 1, true),
+  "iOS build patch compiles the required-import picker bridge")
+
+print("ios_required_import_picker_test: ok")

tests/engine/uwp_native_picker_test.lua

@@ -44,6 +44,46 @@ check(importer.installedPath == [[C:\LocalState\picked_mod.zip]],
 check(removedPath == [[C:\LocalState\picked_mod.zip]],
   "removes the temporary copy after installation")
 
+-- The UWP picker returns a temporary path rather than a mobile staged name.
+-- Required imports must use that same picker and remain scoped to the selected
+-- mod instead of relying on a desktop shell or Android/iOS inbox handling.
+local pickedKind
+love.system.pickFile = function(kind)
+  pickedKind = kind
+  return true
+end
+love.system.getPickedFile = function()
+  love.system.getPickedFile = function() return nil end
+  return [[C:\LocalState\picked_required_import.bin]]
+end
+removedPath = nil
+local required = RomImporter.new(function() end, { launcher = true })
+required.mods = { {
+  id = "needs-source",
+  manifest = {
+    id = "needs-source", name = "Needs source",
+    required_imports = { {
+      id = "source", name = "Source", file = "source.bin",
+      md5 = { "00000000000000000000000000000000" },
+    } },
+  },
+} }
+required._importRequiredSource = function(self, modId, importId, path)
+  self.requiredPath = { modId = modId, importId = importId, path = path }
+  return true
+end
+required:chooseRequiredImport("needs-source", "source")
+check(pickedKind == "required_import", "UWP requests the required-import picker kind")
+required:update(0)
+check(required.requiredPath and required.requiredPath.path
+    == [[C:\LocalState\picked_required_import.bin]],
+  "UWP routes the picked dependency to its declared import")
+check(required.requiredPath.modId == "needs-source"
+    and required.requiredPath.importId == "source",
+  "UWP preserves the pending mod and import identity")
+check(removedPath == [[C:\LocalState\picked_required_import.bin]],
+  "UWP removes its temporary required-import copy after validation")
+
 love.system.getOS = saved.getOS
 love.system.pickFile = saved.pickFile
 love.system.getPickedFile = saved.getPickedFile

tests/modkit/cases/mod_fetch.lua

@@ -0,0 +1,203 @@
+-- mod.fetch: background HTTP for sandboxed mods, behind the "network"
+-- permission.  The sandbox blocks love.thread because newThread's Lua state
+-- escapes every rule in it; this is the replacement, so the things that make
+-- it NOT an escape are what this file pins -- http/https only, handles that
+-- are opaque and per-mod, a ceiling on jobs in flight, and release on unload.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.modkit")
+local Net = require("src.mods.Net")
+local Fetch = require("src.net.Fetch")
+
+-- Stand in for the worker pool: jobs resolve when the test says so, so no
+-- test here touches a socket.
+local submitted, nextId, states = {}, 0, {}
+Fetch.get = function(url, opts)
+  nextId = nextId + 1
+  submitted[nextId] = { url = url, opts = opts }
+  states[nextId] = { status = "pending", progress = 0 }
+  return nextId
+end
+Fetch.poll = function(id) return states[id] or { status = "error", err = "unknown job" } end
+Fetch.isPending = function(id) return (states[id] or {}).status == "pending" end
+Fetch.release = function(id) states[id] = nil end
+Fetch.cancel = function(id)
+  if states[id] and states[id].status == "pending" then states[id].status = "cancelled" end
+end
+Fetch.available = function() return true end
+
+local FETCHER = {
+  ["mods/net_fetcher/manifest.json"] = [[{
+    "id": "net_fetcher",
+    "name": "Net Fetcher",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2,
+    "permissions": ["network"]
+  }]],
+  ["mods/net_fetcher/main.lua"] = [[
+    local mod = ...
+    mod.exports.available = mod.fetch:available()
+    mod.exports.get = function(url, opts) return mod.fetch:get(url, opts) end
+    mod.exports.poll = function(h) return mod.fetch:poll(h) end
+    mod.exports.release = function(h) return mod.fetch:release(h) end
+    mod.exports.cancel = function(h) return mod.fetch:cancel(h) end
+  ]],
+}
+
+local OTHER = {
+  ["mods/net_other/manifest.json"] = [[{
+    "id": "net_other",
+    "name": "Net Other",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2,
+    "permissions": ["network"]
+  }]],
+  ["mods/net_other/main.lua"] = [[
+    local mod = ...
+    mod.exports.poll = function(h) return mod.fetch:poll(h) end
+    mod.exports.cancel = function(h) return mod.fetch:cancel(h) end
+    mod.exports.get = function(url) return mod.fetch:get(url) end
+  ]],
+}
+
+local UNPERMISSIONED = {
+  ["mods/net_probe/manifest.json"] = [[{
+    "id": "net_probe",
+    "name": "Net Probe",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2
+  }]],
+  ["mods/net_probe/main.lua"] = [[
+    local mod = ...
+    mod.exports.available = mod.fetch:available()
+    local ok, err = pcall(function() return mod.fetch:get("https://example.com") end)
+    mod.exports.refused = not ok and tostring(err) or false
+  ]],
+}
+
+local function merged(...)
+  local out = {}
+  for _, fixture in ipairs({ ... }) do
+    for path, body in pairs(fixture) do out[path] = body end
+  end
+  return out
+end
+
+-- ---------------------------------------------------- scheme restriction
+-- curl also speaks file://, scp:// and ftp://.  Without this check mod.fetch
+-- would be a filesystem read and the sandbox would be pointless.
+T.eq(Net.urlDenial("https://example.com/i.json"), nil, "https is allowed")
+T.eq(Net.urlDenial("http://example.com/i.json"), nil, "http is allowed")
+T.check(Net.urlDenial("file:///etc/passwd"), "file:// is refused")
+T.check(Net.urlDenial("FILE:///etc/passwd"), "file:// is refused case-insensitively")
+T.check(Net.urlDenial("scp://host/secret"), "scp:// is refused")
+T.check(Net.urlDenial("ftp://host/x"), "ftp:// is refused")
+T.check(Net.urlDenial("/etc/passwd"), "a bare path is refused")
+T.check(Net.urlDenial("https://"), "a url with no host is refused")
+T.check(Net.urlDenial(nil), "a non-string url is refused")
+T.check(Net.urlDenial("file:///x"):find("http", 1, true),
+  "the refusal says what is allowed")
+
+-- ------------------------------------------------------- permissioned use
+local run = T.sdk.loadMods({ "mods/net_fetcher", "mods/net_other" },
+  { fs = T.sdk.memfs(merged(FETCHER, OTHER)) })
+T.eq(#run.errors, 0,
+  "the permissioned mods load clean (" .. tostring(run.errors[1]) .. ")")
+local api = run.loader.exports.net_fetcher
+T.eq(api.available, true, "available() is true with the permission")
+
+local handle, err = api.get("https://example.com/index.json")
+T.check(handle ~= nil, "get() returns a handle (" .. tostring(err) .. ")")
+T.eq(type(handle), "table", "the handle is opaque, not the engine's job id")
+T.eq(api.poll(handle).status, "pending", "a fresh job polls as pending")
+
+-- the mod is named to the server, and cannot pose as the launcher
+local sent
+for _, job in pairs(submitted) do
+  if job.url == "https://example.com/index.json" then sent = job end
+end
+T.check(sent and sent.opts.userAgent:find("net_fetcher", 1, true),
+  "the request identifies the calling mod")
+
+-- a refused url never reaches the pool
+local before = nextId
+local bad, badErr = api.get("file:///etc/passwd")
+T.eq(bad, nil, "a file:// url returns no handle")
+T.check(badErr and badErr:find("http", 1, true), "and says why")
+T.eq(nextId, before, "and never reaches the fetch pool")
+
+-- the body arrives through poll, as a copy
+states[sent and 1 or 1] = { status = "ok", body = "{\"mods\":[]}", progress = 1 }
+local got = api.poll(handle)
+T.eq(got.status, "ok", "a completed job polls ok")
+T.eq(got.body, "{\"mods\":[]}", "and hands over the body")
+got.body = "tampered"
+T.eq(api.poll(handle).body, "{\"mods\":[]}",
+  "poll returns a copy; a mod cannot edit the engine's job table")
+
+-- --------------------------------------------- handles do not cross mods
+-- Fetch keys jobs by integer and the launcher's own downloads live in the
+-- same table, so this is the property that matters most.
+local other = run.loader.exports.net_other
+T.eq(other.poll(handle).status, "error",
+  "another mod cannot poll a handle it does not own")
+T.eq(other.cancel(handle), false,
+  "another mod cannot cancel a handle it does not own")
+T.eq(api.poll({}).status, "error", "a forged handle reads as an error")
+T.eq(api.poll(1).status, "error", "a guessed integer id reads as an error")
+
+-- ------------------------------------------------------ in-flight ceiling
+-- One mod must not be able to fill the shared three-worker pool.
+local held = {}
+for i = 1, Net.MAX_INFLIGHT + 2 do
+  held[i] = select(1, api.get("https://example.com/" .. i))
+end
+local live = 0
+for _, h in ipairs(held) do if h then live = live + 1 end end
+T.check(live <= Net.MAX_INFLIGHT,
+  "a mod is capped at " .. Net.MAX_INFLIGHT .. " requests in flight")
+local _, capErr = api.get("https://example.com/overflow")
+T.check(capErr and capErr:find("in flight", 1, true),
+  "the refusal explains the cap")
+-- releasing frees a slot
+api.release(held[1])
+local after = api.get("https://example.com/after-release")
+T.check(after ~= nil, "releasing a handle frees a slot")
+
+-- the timeout is clamped, so a mod cannot pin a worker
+for _, h in ipairs(held) do if h then api.release(h) end end
+if after then api.release(after) end
+local slow, slowErr = api.get("https://example.com/slow", { maxSeconds = 99999 })
+T.check(slow ~= nil, "a slot is free again (" .. tostring(slowErr) .. ")")
+local slowJob
+for _, job in pairs(submitted) do
+  if job.url == "https://example.com/slow" then slowJob = job end
+end
+T.check(slow and slowJob.opts.maxSeconds <= Net.MAX_SECONDS,
+  "a caller's timeout is clamped to " .. Net.MAX_SECONDS .. "s")
+
+-- ------------------------------------------------------ release on unload
+local loader = run.loader
+T.check(loader.netJobs and loader.netJobs.net_fetcher,
+  "the loader tracks the mod's jobs")
+Net.releaseAll(loader, "net_fetcher")
+T.eq(loader.netJobs.net_fetcher, nil,
+  "unloading a mod drops every job it still held")
+run.release()
+
+-- --------------------------------------------- without the permission
+local probe = T.sdk.loadMods({ "mods/net_probe" },
+  { fs = T.sdk.memfs(UNPERMISSIONED) })
+T.eq(#probe.errors, 0,
+  "the unpermissioned mod loads clean (" .. tostring(probe.errors[1]) .. ")")
+local out = probe.loader.exports.net_probe
+T.eq(out.available, false, "available() is quietly false without the permission")
+T.check(out.refused and out.refused:find('"network" permission', 1, true),
+  "get() without the permission names it")
+probe.release()
+
+T.finish("mod_fetch")

tests/modkit/cases/mod_job.lua

@@ -0,0 +1,176 @@
+-- mod.job: background compute for sandboxed mods, behind the "background"
+-- permission.  The worker rebuilds the mod's sandbox before loading its
+-- script, so what this file pins is the contract that keeps a job from being
+-- love.thread by another name -- plain data only, paths that cannot climb,
+-- handles that do not cross mods, and ceilings on how much a mod can start.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.modkit")
+local Job = require("src.mods.Job")
+
+local WORKER = {
+  ["mods/job_worker_mod/manifest.json"] = [[{
+    "id": "job_worker_mod",
+    "name": "Job Worker",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2,
+    "permissions": ["background"]
+  }]],
+  ["mods/job_worker_mod/main.lua"] = [[
+    local mod = ...
+    mod.exports.available = mod.job:available()
+    mod.exports.run = function(script, arg, opts)
+      return mod.job:run(script, arg, opts)
+    end
+    mod.exports.poll = function(h) return mod.job:poll(h) end
+    mod.exports.release = function(h) return mod.job:release(h) end
+    mod.exports.cancel = function(h) return mod.job:cancel(h) end
+  ]],
+  ["mods/job_worker_mod/jobs/crunch.lua"] = [[
+    local arg = ...
+    local total = 0
+    for i = 1, (arg and arg.n or 0) do total = total + i end
+    return { total = total }
+  ]],
+}
+
+local OTHER = {
+  ["mods/job_other/manifest.json"] = [[{
+    "id": "job_other",
+    "name": "Job Other",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2,
+    "permissions": ["background"]
+  }]],
+  ["mods/job_other/main.lua"] = [[
+    local mod = ...
+    mod.exports.poll = function(h) return mod.job:poll(h) end
+    mod.exports.cancel = function(h) return mod.job:cancel(h) end
+  ]],
+}
+
+local UNPERMISSIONED = {
+  ["mods/job_probe/manifest.json"] = [[{
+    "id": "job_probe",
+    "name": "Job Probe",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2
+  }]],
+  ["mods/job_probe/main.lua"] = [[
+    local mod = ...
+    mod.exports.available = mod.job:available()
+    local ok, err = pcall(function() return mod.job:run("jobs/x.lua") end)
+    mod.exports.refused = not ok and tostring(err) or false
+  ]],
+}
+
+local function merged(...)
+  local out = {}
+  for _, fixture in ipairs({ ... }) do
+    for path, body in pairs(fixture) do out[path] = body end
+  end
+  return out
+end
+
+-- ------------------------------------------------- plain-data enforcement
+-- Nothing but plain data can cross a thread boundary; a function reaching
+-- LÖVE's serialiser fails deep inside it instead of at the mod's own call.
+local okData, dataErr = Job.plain({ a = 1, b = "two", c = { d = true } })
+T.check(okData and okData.c.d == true, "plain data survives the copy")
+T.check(select(2, Job.plain({ f = function() end })),
+  "a function is refused")
+T.check(select(2, Job.plain(function() end)), "a bare function is refused")
+T.check(select(2, Job.plain({ [{}] = 1 })), "a table key is refused")
+local cycle = {}; cycle.self = cycle
+T.check(select(2, Job.plain(cycle)), "a cycle is refused, not hung on")
+local deep = {}
+local cur = deep
+for _ = 1, Job.MAX_DEPTH + 4 do cur.next = {}; cur = cur.next end
+T.check(select(2, Job.plain(deep)), "absurd nesting is refused")
+T.eq(dataErr, nil, "a clean table reports no error")
+
+-- the copy is a copy: mutating the source does not reach the copy
+local src = { n = 1 }
+local copied = Job.plain(src)
+src.n = 99
+T.eq(copied.n, 1, "the payload is snapshotted, not referenced")
+
+-- ------------------------------------------------------- permissioned use
+local run = T.sdk.loadMods({ "mods/job_worker_mod", "mods/job_other" },
+  { fs = T.sdk.memfs(merged(WORKER, OTHER)) })
+T.eq(#run.errors, 0,
+  "the permissioned mods load clean (" .. tostring(run.errors[1]) .. ")")
+local api = run.loader.exports.job_worker_mod
+
+-- The test harness has no love.thread, so run() reports that rather than
+-- pretending; the gating, path and data rules above it still apply and are
+-- what this suite exists to pin.
+local handle, why = api.run("jobs/crunch.lua", { n = 10 })
+if Job.available() then
+  T.check(handle ~= nil, "run() returns a handle (" .. tostring(why) .. ")")
+  T.eq(type(handle), "table", "the handle is opaque")
+else
+  T.eq(handle, nil, "run() reports when the host has no threads")
+  T.check(why and why:find("unavailable", 1, true), "and says so plainly")
+end
+
+-- ------------------------------------------------------ paths cannot climb
+-- A job script is named inside the mod's own folder, the same rule mod:read
+-- follows.  A job is not a way to name a path.
+-- These assert the PATH message specifically: "unavailable" is also truthy,
+-- so a loose check here would pass even with the path rules removed.
+local _, climbErr = api.run("../../../etc/passwd", {})
+T.check(climbErr and climbErr:find("inside its root", 1, true),
+  "a climbing path is refused (" .. tostring(climbErr) .. ")")
+local _, absErr = api.run("/etc/passwd", {})
+T.check(absErr and absErr:find("inside its root", 1, true),
+  "an absolute path is refused")
+local _, driveErr = api.run("C:/windows/system32/x.lua", {})
+T.check(driveErr and driveErr:find("inside its root", 1, true),
+  "a drive-relative path is refused")
+local _, emptyErr = api.run("", {})
+T.check(emptyErr and emptyErr:find("script path", 1, true),
+  "an empty path is refused")
+local _, typeErr = api.run(nil, {})
+T.check(typeErr and typeErr:find("script path", 1, true),
+  "a non-string path is refused")
+
+-- a function in the argument is caught at the mod's call, not in LÖVE
+local _, argErr = api.run("jobs/crunch.lua", { cb = function() end })
+T.check(argErr and argErr:find("plain data", 1, true),
+  "a non-serialisable argument is refused with a reason")
+
+-- ------------------------------------------- handles do not cross mods
+local other = run.loader.exports.job_other
+T.eq(api.poll({}).status, "error", "a forged handle reads as an error")
+T.eq(api.poll(1).status, "error", "a guessed id reads as an error")
+if handle then
+  T.eq(other.poll(handle).status, "error",
+    "another mod cannot poll a handle it does not own")
+  T.eq(other.cancel(handle), false,
+    "another mod cannot cancel a handle it does not own")
+end
+
+-- ------------------------------------------------------------- unload
+local loader = run.loader
+Job.releaseAll(loader, "job_worker_mod")
+T.eq(loader.jobs and loader.jobs.job_worker_mod, nil,
+  "unloading a mod drops every job it still held")
+run.release()
+
+-- --------------------------------------------- without the permission
+local probe = T.sdk.loadMods({ "mods/job_probe" },
+  { fs = T.sdk.memfs(UNPERMISSIONED) })
+T.eq(#probe.errors, 0,
+  "the unpermissioned mod loads clean (" .. tostring(probe.errors[1]) .. ")")
+local out = probe.loader.exports.job_probe
+T.eq(out.available, false, "available() is quietly false without the permission")
+T.check(out.refused and out.refused:find('"background" permission', 1, true),
+  "run() without the permission names it")
+probe.release()
+
+T.finish("mod_job")

tests/modkit/cases/sandbox.lua

@@ -62,6 +62,9 @@ local PROBE = [[
   out.assignGarbage = attempt(function() love.mousemoved = 7 end)
   out.powerInfo = type(love.system.getPowerInfo)
   out.openUrl = love.system.openURL("https://example.com")
+  -- tls* is forwarded from the real love.system when the engine hung it
+  -- (Gen1Tls / Android JNI); without that it's just nil, not an error.
+  out.tlsOpenType = type(love.system.tlsOpen)
   out.eventQuit = love.event.quit()
   out.popen = select(1, io.popen("ls"))
 
@@ -200,6 +203,8 @@ T.check(out.loveAssign ~= false,
   "a mod cannot replace a love module table: " .. tostring(out.loveAssign))
 T.eq(out.powerInfo, "function",
   "love.system reads through to the same information mod.device exposes")
+T.check(out.tlsOpenType == "function" or out.tlsOpenType == "nil",
+  "tls* is readable through the system shim (nil until the engine hangs it)")
 
 -- a wrapped callback has to land on the real table or the wrap never fires
 T.eq(type(installedMouseMoved), "function",

tests/save_editor_gen2_tests.lua

@@ -373,5 +373,25 @@ do
   check(main ~= nil, "saveFilename resolves for gold")
 end
 
+-- Gold's cache has no text_pointers / trainer_headers / field.  Data:load
+-- used to throw in seedDefaults (self.field.boot) after filling pokemon
+-- with provenance scalars.  That is the Android first-Edit CTD: the APK
+-- cannot fall back to Red's source-tree copies the way a desktop checkout
+-- can.
+do
+  GameVersion.set("gold")
+  local Data = require("src.core.Data")
+  Data.constants = {}
+  Data.pokemon = { generation = 2, CYNDAQUIL = { dex = 155 } }
+  Data.maps = {}
+  Data.field = nil
+  Data.trainer_headers = nil
+  local ok, err = pcall(function() Data:seedDefaults() end)
+  check(ok, "gold seedDefaults survives a Gold-shaped cache: " .. tostring(err))
+  check(type(Data.field) == "table", "seedDefaults creates field when Gold omitted it")
+  eq(Data.constants.dexSize, 155, "dexSize ignores pokemon.generation scalar")
+  GameVersion.set("red")
+end
+
 print(string.format("save editor gen2 tests: %d passed, %d failed", passed, failed))
 if failed > 0 then os.exit(1) end

tools/save-editor/App.lua

@@ -146,7 +146,7 @@ function App.load(pathOverride, opts)
   -- the same mod set the game loads, merged into Data before the catalogs
   -- build, so modded species/items/moves are editable and MonOps stops
   -- asserting on them
-  if not mods then
+  if not mods or App.dataVersion ~= opts.version then
     -- One loader per editor session.  A previous session leaves Data holding
     -- that session's merged registries (and possibly the other game's cache),
     -- and a second builtin registration over them collides -- "statuses

tools/save-editor/Catalog.lua

@@ -40,10 +40,11 @@ end
 
 local function shellListLua(dir)
   local out = {}
+  if not (io and io.popen) then return out end
   if package.config:sub(1, 1) == "\\" then
     -- cmd has no ls; dir /b prints bare names, so re-attach the directory
-    local p = io.popen(string.format('dir /b "%s\\*.lua" 2>nul', dir))
-    if p then
+    local ok, p = pcall(io.popen, string.format('dir /b "%s\\*.lua" 2>nul', dir))
+    if ok and p then
       for line in p:lines() do
         if line ~= "" then table.insert(out, dir .. "/" .. line) end
       end
@@ -51,8 +52,8 @@ local function shellListLua(dir)
     end
     return out
   end
-  local p = io.popen(string.format('ls "%s"/*.lua 2>/dev/null', dir))
-  if p then
+  local ok, p = pcall(io.popen, string.format('ls "%s"/*.lua 2>/dev/null', dir))
+  if ok and p then
     for line in p:lines() do
       table.insert(out, line)
     end
@@ -64,8 +65,8 @@ end
 local function readText(path)
   local fs = love and love.filesystem
   if fs and fs.read and fs.getInfo and fs.getInfo(path) then
-    local body = fs.read(path)
-    if body then return body end
+    local ok, body = pcall(fs.read, path)
+    if ok and body then return body end
   end
   local f = io.open(path, "r")
   if not f then return nil end
@@ -78,7 +79,7 @@ end
 -- scripts show up beside the vanilla EVENT_ ones
 function Catalog.scrapeEvents(scriptDir, headerPath, listFiles, extraDirs)
   listFiles = listFiles or function(dir)
-    return loveListLua(dir) or shellListLua(dir)
+    return loveListLua(dir) or shellListLua(dir) or {}
   end
 
   local found = {}
@@ -97,7 +98,8 @@ function Catalog.scrapeEvents(scriptDir, headerPath, listFiles, extraDirs)
     dirs[#dirs + 1] = dir
   end
   for _, dir in ipairs(dirs) do
-    for _, path in ipairs(listFiles(dir)) do
+    local files = listFiles(dir) or {}
+    for _, path in ipairs(files) do
       local body = readText(path)
       if body then eat(body) end
     end

tools/save-editor/Gen.lua

@@ -78,15 +78,28 @@ function Gen.bindGoldData(data)
   if data.palettes and data.gen2Palettes == nil then
     data.gen2Palettes = data.palettes
   end
-  if data.gen2Roofs == nil and data.roofs == nil then
-    local ok, roofs = pcall(require, "data.generated.roofs")
-    if ok and type(roofs) == "table" then
-      data.roofs = roofs
-      data.gen2Roofs = roofs
+
+  local loadGen = function(rel)
+    local CacheFs = require("src.import.CacheFs")
+    local bytes = CacheFs.readActive("data/generated/" .. rel .. ".lua")
+    if type(bytes) == "string" then
+      local chunk = loadstring(bytes, "@gold/data/generated/" .. rel .. ".lua")
+      if chunk then
+        local ok, res = pcall(chunk)
+        if ok and type(res) == "table" then return res end
+      end
     end
-  elseif data.roofs and data.gen2Roofs == nil then
-    data.gen2Roofs = data.roofs
+    local ok, res = pcall(require, "data.generated." .. rel)
+    if ok and type(res) == "table" then return res end
+    return nil
   end
+
+  data.gen2Palettes = data.gen2Palettes or loadGen("palettes")
+  data.gen2Icons = data.gen2Icons or loadGen("icons")
+  data.gen2Pokedex = data.gen2Pokedex or loadGen("pokedex")
+  data.gen2Landmarks = data.gen2Landmarks or loadGen("landmarks")
+  data.gen2Roofs = data.gen2Roofs or loadGen("roofs") or data.roofs
+  data.gen2Sprites = data.gen2Sprites or loadGen("sprites")
   return data
 end
 
@@ -213,10 +226,15 @@ function Gen.playerMap(save)
   if Gen.of(save) == 2 then
     local p = save.position
     if p and p.map then return p.map, p.x or 0, p.y or 0, p.facing end
-    return save.spawn, 0, 0
+    if type(save.spawn) == "table" then
+      return save.spawn.map or "PLAYERS_HOUSE_2F", save.spawn.x or 0, save.spawn.y or 0, save.spawn.facing
+    elseif type(save.spawn) == "string" then
+      return save.spawn, 0, 0
+    end
+    return "PLAYERS_HOUSE_2F", 3, 3
   end
   local p = save.player or {}
-  return p.map, p.x or 0, p.y or 0
+  return p.map or "REDS_HOUSE_2F", p.x or 0, p.y or 0
 end
 
 function Gen.setPlayerHere(save, mapId, x, y, facing)