Merge pull request #1306 from bryanthaboi/dev

for greg

data/scripts/story2.lua

@@ -178,7 +178,8 @@ M.PALLET_TOWN = {
       end
     end
 
-    local function enterLab()
+    local function enterLab(oak)
+      if oak then oak.stepFrames = nil end
       Commands.hide_object(ctx, "PALLET_TOWN", "PALLETTOWN_OAK")
       Commands.show_object(ctx, "OAKS_LAB", "OAKSLAB_OAK2")
       ow.doorWarp = true
@@ -187,12 +188,17 @@ M.PALLET_TOWN = {
     end
 
     local function walkToLab(oak)
+      -- lockstep half runs Oak on the player's own frames per cell
+      -- engine/overworld/movement.asm:737 (DoScriptedNPCMovement)
       local i = 0
+      if oak then
+        oak.stepFrames = ow.player.stepFramesCur or ow.player.stepFrames
+      end
       local function tick()
         i = i + 1
         local playerStep = escort.playerSteps[i]
         if not playerStep then
-          enterLab()
+          enterLab(oak)
           return
         end
         if oak and escort.oakSteps[i] then

data/scripts/story5.lua

@@ -446,7 +446,7 @@ local function pewterGymEscort(game, ow)
   end
 
   local function afterWalk()
-    if guy then guy.facing = "left" end
+    if guy then guy.stepFrames, guy.facing = nil, "left" end
     Music.playMap(game.data, "PEWTER_CITY")
     push(game, t._PewterCityYoungsterGoTakeOnBrockText
       or "Go take on BROCK\nat the GYM first!", walkHome)
@@ -469,6 +469,11 @@ local function pewterGymEscort(game, ow)
   end
 
   local function beginWalk()
+    -- the escort runs the youngster on the player's own frames per cell
+    -- engine/overworld/movement.asm:737 (DoScriptedNPCMovement)
+    if guy then
+      guy.stepFrames = ow.player.stepFramesCur or ow.player.stepFrames
+    end
     Music.play(game.data, "Music_MuseumGuy")
     if guy and head > 0 then
       local h = 0

docs/mod-api-gen2-compat.md

@@ -240,7 +240,7 @@ resolves to the weaker claim:
 | `warned` | present, answers nil or degrades, and names itself once with the mod attributed |
 | `absent` | deliberately not served; a nil read is the honest failure |
 
-Today that is 288 backed, 32 warned and 161 absent across the fifteen modules.
+Today that is 291 backed, 32 warned and 161 absent across the fifteen modules.
 `notes` keys are documentation topics rather than a member list -- dotted paths
 (`save.money`), field names (`warpAt`), hook names (`hook ui.pc.items`) and
 bare topics (`identity`, `iteration`, `rawset`) all appear there. `members` is
@@ -486,6 +486,9 @@ has its own entry points for (`start_battle "wild" species level`, `warp`,
 **by name, before the first row runs**, so a mod never gets a half-run queue.
 `marchInPlace` still has no Gen 2 equivalent (the Gen 2 movement stream has no
 byte for it) and returns `nil, reason` rather than approximating one.
+`availableFieldActions` and `useFieldAction` expose the same contextual
+bicycle and fishing records in both games. Each engine keeps ownership of its
+inventory, terrain, surfing, bike, and fishing rules.
 
 **Hooks and events that fire on Gold.** Every name below is the Gen 1 name
 carrying the Gen 1 payload keys, because Gold's call sites reuse them rather
@@ -763,6 +766,11 @@ name and the existing payload, plus fields where Gen 2 genuinely carries more
 
 The list is much shorter than it was. What is outstanding, in descending value:
 
+- `trainer.before_battle`: Gold constructs and pushes its trainer battle in
+  `src/world/gen2/World.lua:startBattle`, which does not yet expose a deferred
+  preparation boundary or a battle-local player-party view. Gen 1 mods can use
+  the hook documented in `docs/modding.md`; do not claim Gold compatibility
+  when that selection is required.
 - `pokemon.before_give` / `pokemon.received`: Gold has no give-mon seam of its
   own yet.
 - `link.*` and `trade.completed`: a Gold boot offers no link menu at all. The

docs/modding.md

@@ -147,6 +147,20 @@ Companion UIs and alternate party screens can call
 operation is accepted only during idle overworld play; menus, movement,
 scripts, battles, and transitions leave the party untouched.
 
+## Contextual field items
+
+`mod.world:availableFieldActions()` returns the field items that can start at
+the player's current position. Red and Gold currently expose `bicycle` and
+`fish`; fishing rows include the owned rods that are valid choices. The list
+is empty while the world is busy, while riding states or terrain forbid an
+action, or when the required item is not owned.
+
+Call `mod.world:useFieldAction(id, opts)` to perform a listed action through
+the active game's own field-item path. Fishing accepts `{ rod = "OLD_ROD" }`
+and chooses automatically when only one rod is available. Invalid, stale, and
+busy requests return `nil` plus a reason without changing game state. Mods do
+not need generation-specific bike, collision, or fishing logic.
+
 ## Rendering pipelines
 
 Most registries hand the engine *content*. `render_pipelines` hands it
@@ -308,6 +322,25 @@ local keys, code, message = mod.storage:list(game, "history/quick")
 local deleted, code, message = mod.storage:delete(game, "history/quick/q0001")
 ```
 
+For independently generated binary data, use the opaque byte methods. They
+accept and return the exact Lua string of bytes, including NUL bytes and bytes
+that are not valid text:
+
+```lua
+local ok, code, message = mod.storage:writeBytes(
+  game, "cache/maps/pallet/terrain", encodedMesh)
+local encodedMesh, code, message = mod.storage:readBytes(
+  game, "cache/maps/pallet/terrain")
+```
+
+Opaque values are limited to 512 MiB per key. The engine stores them without
+decoding, compression, or an engine-defined file format, and never executes
+them. A consuming mod owns validation of its format, fingerprint, checksum,
+and compression metadata. Byte writes are staged and compared byte-for-byte
+before replacement, and reads can recover a valid backup after an interrupted
+write. Existing table values and opaque byte values use one shared logical key
+space; delete a key before changing its value from one type to the other.
+
 `context` returns `{ engineVersion, gameVersion, playthroughId }`. The engine
 version is compatibility metadata; physical launcher-slot and path identity stays
 private. A title-selected context may additionally contain `normalSavedAt`, the
@@ -316,19 +349,22 @@ progress or a slot/path handle.
 
 At the title screen only, `mod.storage:selected(game)` returns a bound storage
 facade for the launcher-selected existing playthrough, or `nil, code, message`.
-Resolving this facade is read-only: it never allocates an identity, adopts a
+Resolving this facade is non-allocating: it never allocates an identity, adopts a
 fresh New Game, or exposes a slot id/path. Its `context()`, `read(key)`,
-`write(key, value)`, `list(prefix)`, and `delete(key)` methods have the same
-data-only and transaction contract as `mod.storage`, but remain restricted to
-the calling mod's selected existing namespace. It is intended for title tools
-that need to browse or manage durable history before the first normal SAVE.
+`write(key, value)`, `readBytes(key)`, `writeBytes(key, bytes)`,
+`list(prefix)`, and `delete(key)` methods have the same scoped and
+transactional contract as `mod.storage`, but remain restricted to the calling
+mod's selected existing namespace. It is intended for title tools that need to
+browse or manage durable history before the first normal SAVE.
 
-Values must be tables containing serializable data only. Keys are conservative
-slash-separated segments (letters, digits, `_`, `-`); paths and filesystem
-handles are never exposed. Writes are staged and decode-verified, reads recover
-from a valid staged/backup generation, and methods return structured errors for
-normal data or I/O failures. The playthrough identity is allocated lazily on the
-first storage/checkpoint call, so an unused API changes no save bytes.
+Table values must contain serializable data only. Opaque values must be Lua
+strings. Keys are conservative slash-separated segments (letters, digits, `_`,
+`-`); paths and filesystem handles are never exposed. Table writes are staged
+and decode-verified; opaque writes are staged and byte-verified; reads recover
+from a valid staged/backup generation. Methods return structured errors for
+normal data, byte validation, and I/O failures. The playthrough identity is
+allocated lazily on the first storage/checkpoint call, so an unused API changes
+no save bytes.
 
 `mod.checkpoints` captures and reconstructs engine-owned semantic runtime state:
 
@@ -423,6 +459,43 @@ animation/messages, forced choices, and every phase that cannot safely be
 checkpointed remain excluded. Exceptions are contained by normal hook isolation
 and fall through without advancing a turn.
 
+Gen 1 trainer encounters also expose `trainer.before_battle` after the
+challenge text and immediately before battle construction. This lets a mod
+defer the encounter while it collects a player choice through a registered
+screen, then resume with a battle-local view of the save party:
+
+```lua
+mod.hooks:wrap("trainer.before_battle", function(next, game, context, continue)
+  -- context = { trainerClass, partyIndex, mapId, npcId }
+  mod.ui.push(game, "party_registration", {
+    onConfirm = function(indices)
+      continue({ playerPartyIndices = indices })
+    end,
+    onCancel = function()
+      continue({ cancel = true })
+    end,
+  })
+  return true
+end)
+```
+
+Return `true` only when retaining `continue` for a later callback. Calling
+`continue({ cancel = true })` ends the encounter without constructing a battle;
+the normal encounter completion callback returns control to the overworld and
+no trainer-defeated state is written. A cancelled sight encounter is suppressed
+at the current player cell so it cannot immediately reopen; moving one cell or
+talking to the trainer permits a new challenge. Calling `continue()` uses the
+full save party; passing
+`{ playerPartyIndices = { 2, 4, 5 } }` uses those ordered, one-based party
+members for initial send, switching and forced replacement, exhaustion,
+experience traversal, and battle party displays. The continuation is one-shot.
+An empty, duplicate, out-of-range, or otherwise malformed list safely falls
+back to the full party. The view references the original Pokemon records and
+never reorders or replaces `game.save.party`; trainer battle checkpoints retain
+the selected indices. Mods remain responsible for selection policy and should
+use only public `mod.ui`, hook, and save APIs. See RFC 0010 for the exact
+contract and compatibility guarantees.
+
 ## Developer console
 
 Boot with developer mode on to unlock the in-game console and hot-reload

docs/modding/reference/registries.md

@@ -929,6 +929,10 @@ mod.content.sfx:register("SFX_MOD_CHIME", { file = "chime.ogg" })
 
 | field | type | required |
 |---|---|---|
+| `anchorX` | number | no |
+| `anchorY` | number | no |
+| `frameHeight` | integer >= 1 | no |
+| `frameWidth` | integer >= 1 | no |
 | `frames` | integer >= 1 | yes |
 | `id` | string | no |
 | `image` | file path | yes |
@@ -1100,6 +1104,7 @@ mod.content.tokens:register("CLOCK", function(game) return "12" end)
 | `paletteSource` | string | no |
 | `parties` | list of list of {level, species} | yes |
 | `pic` | file path | no |
+| `trueColor` | boolean | no |
 
 ```lua
 mod.content.trainers:patch("OPP_BROCK", { baseMoney = 99 })
@@ -1122,7 +1127,9 @@ do not.
 | `index` | integer 0..255 | no |
 | `items` | list of items id | no |
 | `name` | string | yes |
+| `pic` | file path | no |
 | `trainers` | list of {id?, index?, name, party, trainerType?} | yes |
+| `trueColor` | boolean | no |
 
 ```lua
 mod.content.trainers:patch("BEAUTY", { baseMoney = 99 })

docs/preparing-your-mod-for-gen2.md

@@ -325,7 +325,7 @@ This is not a dev-mode feature; it installs on any Gold boot that has mods.
 | `src.pokemon.Boxes` | facade | over `src/core/gen2/Boxes.lua` | 22 / 0 / 0 |
 | `src.battle.BattleState` | facade | over `src/ui/gen2/BattleState.lua` | 16 / 2 / 39 |
 | `src.ui.PartyMenu` | facade | over `src/ui/gen2/PartyMenu.lua` | 15 / 2 / 16 |
-| `src.world.WorldAPI` | alias | `src/world/gen2/WorldAPI.lua` | 12 / 2 / 0 |
+| `src.world.WorldAPI` | alias | `src/world/gen2/WorldAPI.lua` | 15 / 2 / 0 |
 | `src.world.PikachuFollower` | alias | `src/world/gen2/Follower.lua` | 10 / 0 / 11 |
 | `src.script.ScriptRunner` | facade | over `src/script/gen2/Vm.lua` | 10 / 7 / 1 |
 | `src.ui.OptionsMenu` | facade | over `src/ui/gen2/OptionsMenu.lua` | 8 / 0 / 1 |
@@ -774,7 +774,7 @@ profile to test in, and `POKEPORT_DEV=1` adds the console and `F5` hot reload.
 
 - **Coverage is partial and will stay partial.** 15 Gen 1 modules are served
   out of a much larger engine, and within those 15 the coverage table records
-  288 backed members against 32 warned and 161 absent. The absent ones are not
+  291 backed members against 32 warned and 161 absent. The absent ones are not
   a backlog; most are absent because there is no honest Gen 2 answer, and each
   one carries its reason. The counts move as the adapter learns something: a
   member that turns out to answer nil is demoted from backed to warned or

docs/rfcs/0003-playthrough-storage.md

@@ -26,8 +26,8 @@ wiki's Save Model. `mod.save` and `mod.options` keep their existing behavior.
 ## The exact API delta
 
 Backward-compatible, additive-only. `Loader:_api` binds a new `mod.storage`
-facade to the calling mod id. Mods receive logical keys and decoded values, never
-filesystem handles or physical paths.
+facade to the calling mod id. Mods receive logical keys and either decoded table
+values or exact opaque byte strings, never filesystem handles or physical paths.
 
 ### Lazy opaque playthrough identity
 
@@ -75,6 +75,25 @@ Returns a freshly decoded table, or `nil, code, message`. It tries main, staged,
 then backup data. A valid staged/backup value is returned and promoted
 best-effort; corrupt bytes are never executed.
 
+### `mod.storage:writeBytes(game, key, bytes)`
+
+Accepts a Lua string containing opaque bytes and returns `true`, or
+`false, code, message`. Empty strings are valid. Payloads are limited to 512
+MiB per key. The engine writes the supplied bytes exactly as received, without
+decoding, compression, checksums, or an engine-defined envelope. The consuming
+mod owns semantic validation of its format.
+
+Byte records use private `.bin`, `.bin.tmp`, and `.bin.bak` witnesses. A staged
+and replacement write is read back and compared byte-for-byte before it is
+committed. A failed write leaves the previous verified generation readable.
+Byte storage never passes its payload to the Lua serializer, loader, or module
+resolver.
+
+Table and byte records share one logical key namespace and a key has one type.
+Writing one type over the other returns `type_conflict`; callers must delete the
+key before changing its type. `mod.storage:selected(game)` exposes the same
+`readBytes` and `writeBytes` operations for the selected playthrough facade.
+
 ### `mod.storage:list(game[, prefix])`
 
 Returns sorted logical keys beneath a valid prefix, an exact key when the prefix
@@ -92,9 +111,9 @@ Physical records are scoped as:
 `persistence root / mod_storage / game version / playthrough id / mod id`
 
 Stable error codes are `not_in_playthrough`, `storage_unavailable`,
-`invalid_key`, `encode_failed`, `write_failed`, `verify_failed`, and
-`not_found`. Ordinary data and I/O failures are return values, not callback-
-terminating errors.
+`invalid_key`, `encode_failed`, `invalid_bytes`, `size_limit`, `type_conflict`,
+`type_mismatch`, `write_failed`, `verify_failed`, and `not_found`. Ordinary
+data and I/O failures are return values, not callback-terminating errors.
 
 The restricted serializer's recursive writer runs outside LuaJIT traces. A
 1,000-process GC stress regression found compiled recursion could intermittently
@@ -107,6 +126,8 @@ boundary.
 **Nothing.** No API is removed, no manifest field changes, and no storage path or
 playthrough id is created unless a mod invokes `mod.storage` or
 `mod.checkpoints`. Existing save bytes remain unchanged on the no-caller path.
+Existing files outside the scoped storage contract are not imported; a caller
+must rebuild them through `writeBytes`.
 
 ## Parity tests
 
@@ -115,8 +136,10 @@ playthrough id is created unless a mod invokes `mod.storage` or
 - **Engine identity:** lazy allocation, save/load preservation, stable legacy
   mapping, fresh-playthrough replacement, and version/slot isolation.
 - **Public Mod API:** two real API-2 entry chunks prove data-only roundtrip,
+  opaque byte roundtrip including NUL bytes, no execution, size/type rejection,
   deterministic listing, key rejection, mod/game/playthrough isolation,
-  corrupt-main recovery, failure retention, exact delete, and no-mod no-write.
+  corrupt-main recovery, failure retention, selected-playthrough access, exact
+  delete, and no-mod no-write.
 
 ## Deprecation etiquette
 

docs/rfcs/0010-trainer-battle-party-scope.md

@@ -0,0 +1,92 @@
+# RFC 0010: Deferred trainer preparation and battle-local party scope
+
+## Status
+
+Proposed.
+
+## Motivation
+
+Challenge and tournament mods sometimes need a player to choose an eligible
+subset of the save party before a trainer battle. The current public surface
+can replace the opponent through `trainer.party` and observe
+`world.trainer_engaged`, but it cannot pause the engagement before battle
+construction or keep unselected save-party members out of initial send,
+switch, replacement, exhaustion, experience, and party-menu traversal.
+
+Temporarily rewriting `game.save.party` is not a safe substitute: it changes
+authoritative save state, composes poorly with checkpoints and other mods, and
+can strand excluded Pokémon if a callback or process fails.
+
+## Decision and plan extended
+
+This implements **D-AT-001: battle-local Gym registration without save-party
+mutation**, the consuming design decision tracked as capability `AT-SP-001` in
+the Adaptive Trainers implementation plan. The plan file is
+[`docs/superpowers/plans/2026-08-14-adaptive-trainers.md`](https://github.com/MaxTomahawk/gen1recomp-adaptive-trainers/blob/main/docs/superpowers/plans/2026-08-14-adaptive-trainers.md),
+Task 5. The engine delta also extends the additive, guarded public-hook
+decision used by RFC 0007 and the screen facade documented in
+`docs/modding.md`; it deliberately contains none of the consuming mod's Gym
+or party-size policy.
+
+## Exact API delta
+
+Add the guarded hook:
+
+```lua
+mod.hooks:wrap("trainer.before_battle", function(next, game, context, continue)
+  -- context = { trainerClass, partyIndex, mapId, npcId }
+  -- Return true only when the battle has been deferred.
+  -- continue({ cancel = true }) returns without constructing a battle.
+  -- Call continue() for the full save party, or:
+  -- continue({ playerPartyIndices = { 2, 4, 5 } })
+end)
+```
+
+The hook runs after the trainer's challenge text and immediately before the
+trainer battle is constructed. A mod may push a registered screen with
+`mod.ui.push`, return `true`, and retain `continue` for its confirm/cancel
+callback. `continue` is one-shot and returns `false` after the first call.
+Returning anything other than `true` without calling it continues immediately
+with vanilla scope. With no subscriber, no context or continuation is built.
+
+`playerPartyIndices` is an ordered, one-based list into `game.save.party`.
+Valid unique indices create `battle.playerParty` as a battle-local view of the
+same Pokémon records; the save party itself is never reordered or replaced.
+Malformed or empty scopes degrade to the full party. The view governs initial
+send, all battle party menus and targets, voluntary and forced replacement,
+exhaustion/blackout checks, participant and EXP.ALL traversal, party counts,
+and party-ball presentation. Checkpoints preserve the index list and rebuild
+the same view before restoring battlers.
+
+`{ cancel = true }` ends a deferred encounter through its normal completion
+callback without constructing a battle or writing trainer-defeated state. A
+cancelled sight encounter is suppressed while the player remains on the same
+cell, preventing immediate reacquisition; moving or directly talking permits a
+new challenge. Cancellation is also one-shot; if supplied alongside a party
+index list, cancellation wins.
+
+The API sets no maximum, chooses no members, identifies no boss, and contains
+no scaling or challenge policy.
+
+## Migration and compatibility
+
+Existing mods change nothing. `BattleState.newTrainer(game, class, index)`
+keeps its current behavior; the optional fourth argument is additive. Existing
+battle checkpoints without a party scope restore against the full save party.
+Wild, Safari, link, and no-mod battles are unchanged.
+
+## Verification
+
+- The catalog-driven hook gate proves empty-chain parity and the guarded hot
+  path proves no-mod engagement starts exactly once without allocation.
+- A sandboxed fixture mod defers through its public hook facade, inspects the
+  data-only context, and resumes once with ordered indices.
+- Engine tests cover initial send, party menus, replacement/exhaustion,
+  EXP traversal, invalid-scope fallback, and save-party identity.
+- Battle-checkpoint tests prove scoped capture/restore and old-checkpoint
+  compatibility.
+
+## Deprecation etiquette
+
+Nothing is deprecated. The hook and optional constructor argument are
+additive.

mobile/ios/app-repo.json

@@ -12,6 +12,20 @@
       "tintColor": "3b5ca8",
       "category": "games",
       "versions": [
+        {
+          "version": "0.1.86",
+          "date": "2026-08-14",
+          "size": 11306689,
+          "downloadURL": "https://github.com/bryanthaboi/gen1recomp/releases/download/v0.1.86/gen1recomp++-0.1.86-ios.ipa",
+          "localizedDescription": "Download the correct version for your computer below.\n\n## Issues closed\n\n- #1283 Intro broken and leading to softlock (R,B,Y currently unplayable without save file)\n\n## Contributors\n\n- @bryanthaboi"
+        },
+        {
+          "version": "0.1.85",
+          "date": "2026-08-14",
+          "size": 11306462,
+          "downloadURL": "https://github.com/bryanthaboi/gen1recomp/releases/download/v0.1.85/gen1recomp++-0.1.85-ios.ipa",
+          "localizedDescription": "Download the correct version for your computer below.\n\n## Contributors\n\n- @bryanthaboi"
+        },
         {
           "version": "0.1.84",
           "date": "2026-08-14",

src/battle/BattleState.lua

@@ -316,6 +316,27 @@ function BattleState.trainerPicPath(data, trainer, oppClass, partyIndex)
   return base and base.pic or nil
 end
 
+-- trueColor on the trainer record, or on the basePic it reuses when the
+-- subclass does not set the flag itself.  Explicit false stays false.
+function BattleState.trainerTrueColor(data, trainer)
+  if not trainer then return false end
+  if trainer.trueColor ~= nil then
+    return trainer.trueColor and true or false
+  end
+  local base = trainer.basePic and data and data.trainers
+    and data.trainers[trainer.basePic]
+  return (base and base.trueColor) and true or false
+end
+
+-- Load a trainer frontpic through getImage so a trueColor portrait skips
+-- the 4-shade quantize the same way a species pic does.
+function BattleState.trainerSprite(data, trainer, oppClass, partyIndex)
+  return getImage(
+    BattleState.trainerPicPath(data, trainer, oppClass, partyIndex),
+    BattleState.trainerPalette(data, trainer),
+    BattleState.trainerTrueColor(data, trainer))
+end
+
 -- The battle-BGP fade variant of a pic (AnimationFlashScreen and the
 -- SetAnimationBGPalette effects remap the four BG shades; on the SGB
 -- the colorizer then colors the REMAPPED shade, so a faded pic shows
@@ -617,6 +638,44 @@ local function newBattle(game)
   return self
 end
 
+local function scopedPlayerParty(game, indices)
+  if indices == nil then return nil, nil end
+  if type(indices) ~= "table" then
+    Logger.warn("trainer battle party scope is not a table; using full party")
+    return nil, nil
+  end
+  local count = #indices
+  local keyCount = 0
+  for key in pairs(indices) do
+    keyCount = keyCount + 1
+    if type(key) ~= "number" or key % 1 ~= 0 or key < 1 or key > count then
+      Logger.warn("trainer battle party scope is malformed; using full party")
+      return nil, nil
+    end
+  end
+  if count == 0 or keyCount ~= count then
+    Logger.warn("trainer battle party scope is empty or sparse; using full party")
+    return nil, nil
+  end
+  local party, normalized, seen = {}, {}, {}
+  for i = 1, count do
+    local index = indices[i]
+    if type(index) ~= "number" or index % 1 ~= 0
+        or not game.save.party[index] or seen[index] then
+      Logger.warn("trainer battle party scope contains an invalid index; using full party")
+      return nil, nil
+    end
+    seen[index] = true
+    normalized[i] = index
+    party[i] = game.save.party[index]
+  end
+  return party, normalized
+end
+
+function BattleState:playerPartyView()
+  return self.playerParty or self.game.save.party
+end
+
 -- opts.hooked: rod encounter, announced with _HookedMonAttackedText
 function BattleState.newWild(game, species, level, opts)
   local self = newBattle(game)
@@ -692,13 +751,15 @@ local function applySpecialMoves(data, oppClass, partyIndex, party)
   end
 end
 
-function BattleState.newTrainer(game, oppClass, partyIndex)
+function BattleState.newTrainer(game, oppClass, partyIndex, opts)
   local self = newBattle(game)
   self.kind = "trainer"
   self.oppClass = oppClass
   -- the object_event trainer arg (roster index).  computeMusicKind keys
   -- data/scripts/victories.lua on class#party, so keep it on the battle (#782).
   self.partyIndex = partyIndex or 1
+  self.playerParty, self.playerPartyIndices = scopedPlayerParty(game,
+    type(opts) == "table" and opts.playerPartyIndices or nil)
   self.trainer = game.data.trainers[oppClass]
   assert(self.trainer, "unknown trainer class " .. tostring(oppClass))
   -- pret GetTrainerName_: RIVAL1/2/3 copy wRivalName into wTrainerName
@@ -742,7 +803,7 @@ function BattleState.newTrainer(game, oppClass, partyIndex)
     end
   end
   self.enemyIndex = 1
-  local playerMon = Party.firstHealthy(game.save.party)
+  local playerMon = Party.firstHealthy(self:playerPartyView())
   if not playerMon then
     Logger.warn("trainer battle with no healthy party; skipping")
     self.dead = true
@@ -756,9 +817,8 @@ function BattleState.newTrainer(game, oppClass, partyIndex)
   -- MonsterPalettes[0] = PAL_MEWMON -- InitBattleCommon zeroes
   -- wEnemyMonSpecies2 before the intro's SET_PAL_BATTLE
   -- (engine/battle/core.asm:6682, engine/gfx/palettes.asm SetPal_Battle)
-  self.trainerPic = getImage(
-    BattleState.trainerPicPath(game.data, self.trainer, oppClass, partyIndex),
-    BattleState.trainerPalette(game.data, self.trainer))
+  self.trainerPic = BattleState.trainerSprite(
+    game.data, self.trainer, oppClass, partyIndex)
   self.introText = Strings("%s wants\nto fight!", self.trainer.name)
   return self
 end
@@ -2002,7 +2062,7 @@ function BattleState:update(dt)
     -- loops the party menu until a healthy mon is picked, so B and
     -- fainted picks land back here and reopen it
     if self.player.mon.hp <= 0 then
-      if Party.firstHealthy(self.game.save.party) then
+      if Party.firstHealthy(self:playerPartyView()) then
         self:openReplacementMenu()
       end
       return
@@ -3890,7 +3950,8 @@ function BattleState:awardExp()
   -- (RemoveFaintedPlayerMon), so it drops out of the divisor and only
   -- the surviving participants are counted and paid
   local participants, alive = 0, {}
-  for _, mon in ipairs(self.game.save.party) do
+  local playerParty = self:playerPartyView()
+  for _, mon in ipairs(playerParty) do
     if self.participants and self.participants[mon] then
       participants = participants + 1
       if mon.hp > 0 then table.insert(alive, mon) end
@@ -3984,9 +4045,9 @@ function BattleState:awardExp()
       -- experience.asm:9-13); each mon gets its own GainedText with the
       -- "with EXP.ALL," tail (wBoostExpByExpAll) -- pokered prints no
       -- summary line
-      for _, mon in ipairs(self.game.save.party) do
+      for _, mon in ipairs(playerParty) do
         if mon.hp > 0 then
-          ctx.applyShare(mon, math.max(1, ctx.participants) * #self.game.save.party * 2, "expAll")
+          ctx.applyShare(mon, math.max(1, ctx.participants) * #playerParty * 2, "expAll")
         end
       end
     end
@@ -4027,7 +4088,7 @@ function BattleState:enemyMonFainted()
       local nextName = nextMon.nickname or self.data.pokemon[nextMon.species].name
       local style = tostring((self.game.save.options or {}).battleStyle or "shift")
         :lower()
-      local partyCount = #self.game.save.party
+      local partyCount = #self:playerPartyView()
       -- ReplaceFaintedEnemyMon (core.asm:892-896): DrawEnemyPokeballs puts the
       -- foe's party ball row -- and the HUD chrome PlaceEnemyHUDTiles lays
       -- down under it (draw_hud_pokeball_gfx.asm:9-11, 33-45, 134-141) -- into
@@ -4054,6 +4115,7 @@ function BattleState:enemyMonFainted()
             local game = self.game
             Screens.push(game, "PartyMenu", {
               battle = self,
+              party = self:playerPartyView(),
               forceSwitch = true,
               onSwitch = function(mon)
                 if mon ~= self.player.mon and mon.hp > 0 then
@@ -4226,7 +4288,7 @@ function BattleState.isOaksLabStarterRival(self)
 end
 
 function BattleState:playerMonFainted()
-  local nextMon = Party.firstHealthy(self.game.save.party)
+  local nextMon = Party.firstHealthy(self:playerPartyView())
   -- Being out of useable POKéMON blacks you out even when the battle was
   -- already decided in our favour.  A double faint -- our last mon dying
   -- to residual damage on the turn it lands the KO -- used to hit the
@@ -4299,6 +4361,7 @@ function BattleState:openReplacementMenu()
   self:ui(function()
     return self:buildScreen("PartyMenu", {
       battle = self,
+      party = self:playerPartyView(),
       -- ChooseNextMon: pick immediately (no SWITCH/STATS/CANCEL)
       forceSwitch = true,
       onSwitch = function(mon)
@@ -4779,6 +4842,7 @@ function BattleState:openParty()
   self:ui(function()
     return self:buildScreen("PartyMenu", {
       battle = self,
+      party = self:playerPartyView(),
       onSwitch = function(mon)
         if mon == self.player.mon then
           self:say(Strings("%s is\nalready out!", self.player.name))
@@ -4825,8 +4889,8 @@ function BattleState:finish()
   -- here it did not, so say so rather than silently papering over it.
   -- The old-man / PROF.OAK demo also skips it: the party never fought
   -- (Yellow's Pallet intro runs before the player owns a mon at all).
-  if self.result ~= "lose" and not self.demo
-     and not Party.firstHealthy(self.game.save.party) then
+  if self.kind ~= "link" and self.result ~= "lose" and not self.demo
+     and not Party.firstHealthy(self:playerPartyView()) then
     Logger.warn("battle finished %s with no healthy party; forcing blackout",
                 tostring(self.result))
     self.result = "lose"
@@ -5707,7 +5771,7 @@ function BattleState:drawHUDs(slide)
     for i = 10, 17 do hudTile(0x76, i * 8, 88) end
     hudTile(0x6F, 72, 88)
     love.graphics.setColor(1, 1, 1, 1)
-    self:drawBallRow(self.playerParty or self.game.save.party, 88, 80, 8)
+    self:drawBallRow(self:playerPartyView(), 88, 80, 8)
   end
   local hidePlayer = self.safari or self.demo
   if showStatus and self.player and not hidePlayer and not self.showPlayerBack

src/core/BattleCheckpoint.lua

@@ -44,6 +44,7 @@ local BATTLE_FIELDS = {
   "sideToxic", "isGymLeader", "musicKind", "lastBall", "lockedBall",
   "lowHealthAlarmDisabled", "lowHealthAlarmOn", "victoryMusicPlayed",
   "endBattleText",
+  "playerPartyIndices",
 }
 
 local function partyIndex(party, mon)
@@ -91,6 +92,23 @@ local function integer(value, min, max)
     and value >= (min or -math.huge) and value <= (max or math.huge)
 end
 
+local function exactIndexSet(indices, maxIndex, requireMember)
+  if type(indices) ~= "table" then return nil end
+  local count, keys = #indices, 0
+  for key in pairs(indices) do
+    keys = keys + 1
+    if not integer(key, 1, count) then return nil end
+  end
+  if keys ~= count or (requireMember and count == 0) then return nil end
+  local seen = {}
+  for i = 1, count do
+    local index = indices[i]
+    if not integer(index, 1, maxIndex) or seen[index] then return nil end
+    seen[index] = true
+  end
+  return seen
+end
+
 local function validateMoveList(data, moves)
   if type(moves) ~= "table" then return false end
   for _, move in ipairs(moves) do
@@ -200,6 +218,16 @@ function BattleCheckpoint.validate(game, checkpoint)
   if type(party) ~= "table" or not validateBattler(game.data, model.player, #party) then
     return nil, "invalid_content", "Player battle state is invalid."
   end
+  local scopedIndices
+  if model.playerPartyIndices ~= nil then
+    if model.kind ~= "trainer" then
+      return nil, "invalid_checkpoint", "Battle party scope is invalid."
+    end
+    scopedIndices = exactIndexSet(model.playerPartyIndices, #party, true)
+    if not scopedIndices or not scopedIndices[model.player.index] then
+      return nil, "invalid_checkpoint", "Battle party scope is invalid."
+    end
+  end
   if model.kind == "wild" then
     if not validateMon(game.data, model.enemyMon)
         or not validateBattler(game.data, model.enemy, 1) then
@@ -220,12 +248,15 @@ function BattleCheckpoint.validate(game, checkpoint)
     end
   end
   for _, indices in ipairs({ model.participants, model.leveledUp }) do
-    if type(indices) ~= "table" then
+    local referenced = exactIndexSet(indices, #party, false)
+    if not referenced then
       return nil, "invalid_checkpoint", "Battle party reference set is missing."
     end
-    for _, index in ipairs(indices) do
-      if not integer(index, 1, #party) then
-        return nil, "invalid_checkpoint", "Battle party reference is invalid."
+    if scopedIndices then
+      for index in pairs(referenced) do
+        if not scopedIndices[index] then
+          return nil, "invalid_checkpoint", "Battle party reference is invalid."
+        end
       end
     end
   end
@@ -276,7 +307,9 @@ function BattleCheckpoint.restore(game, checkpoint, copy)
   local model = checkpoint.runtime.battle
   local battle
   if model.kind == "trainer" then
-    battle = BattleState.newTrainer(game, model.oppClass, model.partyIndex)
+    battle = BattleState.newTrainer(game, model.oppClass, model.partyIndex, {
+      playerPartyIndices = model.playerPartyIndices,
+    })
     battle.enemyParty = assert(copy(model.enemyParty))
     battle.enemyIndex = model.enemyIndex
   else

src/import/RomImporter.lua

@@ -2356,6 +2356,20 @@ function RomImporter:_updatePadCursor(dt)
     local ny = self._padCursor.y + dy * speed * dt
     self._padCursor.x = math.max(ox, math.min(ox + w, nx))
     self._padCursor.y = math.max(oy, math.min(oy + h, ny))
+    -- Pushing INTO the top/bottom edge scrolls the page instead of stalling.
+    -- The cursor is clamped to the safe area above, so on a short window the
+    -- rows below the fold are unreachable on a stickless handheld: no mouse
+    -- wheel, no touchscreen, and no right stick to feed the existing wheel
+    -- path.  Only the OVERSHOOT scrolls -- parking the cursor at the edge does
+    -- nothing, it has to be actively pushed -- and this block only runs on pad
+    -- input, so a real mouse is unaffected.  /48 matches the pixels-per-notch
+    -- LauncherView.draw multiplies back out.
+    local overY = 0
+    if ny > oy + h then overY = ny - (oy + h)
+    elseif ny < oy then overY = ny - oy end
+    if overY ~= 0 and self._flex then
+      require("src.import.LauncherView").wheelmoved(self, 0, -overY / 48)
+    end
     -- Desktop: FlexLove polls the real mouse, so warp it with the pad pointer.
     -- NX: the getPosition bridge already returns pad coords — skip setPosition.
     if not self.isNX and love.mouse.setPosition then

src/mods/Gen2Compat.lua

@@ -737,7 +737,8 @@ COVERAGE["src.pokemon.Boxes"] = {
 COVERAGE["src.world.WorldAPI"] = {
   kind = "alias", target = "src.world.gen2.WorldAPI",
   backed = "new __index overworld current mapOverview warpTo toggleObject replaceBlock "
-    .. "spawnNpc removeNpc npc queueScript invalidateMap",
+    .. "spawnNpc removeNpc npc queueScript invalidateMap "
+    .. "availableFieldActions useFieldAction",
   warned = "setFlag getFlag",
   absent = "",
   notes = {
@@ -1797,7 +1798,8 @@ local function buildBattleState()
     "throwBall", "ballChain", "tossAnimFor", "ballFlicker", "ballMissMessage",
     "storeCaughtMon", "safariAction", "safariEnemyTurn", "drawBallRow",
     "drawClassic", "isWideBattleLayout", "wideLayout", "bgMode", "uiSize",
-    "sgbPalettes", "trainerPalette", "trainerPicPath", "invalidate",
+    "sgbPalettes", "trainerPalette", "trainerPicPath", "trainerTrueColor",
+    "trainerSprite", "invalidate",
     "imageBattleScale", "resolveBattleScale", "backPlacement",
     "frontPlacement", "StatBox", "enter", "exit",
   }) do
@@ -1884,7 +1886,8 @@ COVERAGE["src.battle.BattleState"] = {
   absent = "newWild newTrainer makeSafari makeGhost makeBattler resolveTurn "
     .. "computeDamage catchAttempt runRoll enter exit sgbPalettes "
     .. "isWideBattleLayout wideLayout bgMode uiSize letterboxWhite "
-    .. "holdsUIAnchors BG_WORLD_DIM trainerPalette trainerPicPath invalidate "
+    .. "holdsUIAnchors BG_WORLD_DIM trainerPalette trainerPicPath "
+    .. "trainerTrueColor trainerSprite invalidate "
     .. "backPlacement frontPlacement StatBox drawClassic drawBallRow "
     .. "safariAction safariEnemyTurn throwBall storeCaughtMon field ruleset "
     .. "rng oppClass partyIndex aiUses introText dead",

src/mods/Loader.lua

@@ -1069,7 +1069,8 @@ function Loader:_api(mod)
         bucket[key] = value
       end,
     },
-    -- Data-only state independent of the vanilla progress checkpoint. The
+    -- Data-only and opaque-byte state independent of the vanilla progress
+    -- checkpoint. The
     -- engine binds version/playthrough/mod scope and portable persistence;
     -- callers never receive paths or a raw filesystem handle.
     storage = {
@@ -1077,6 +1078,10 @@ function Loader:_api(mod)
       selected = function(_, game) return storage:selected(game) end,
       write = function(_, game, key, value) return storage:write(game, key, value) end,
       read = function(_, game, key) return storage:read(game, key) end,
+      writeBytes = function(_, game, key, bytes)
+        return storage:writeBytes(game, key, bytes)
+      end,
+      readBytes = function(_, game, key) return storage:readBytes(game, key) end,
       list = function(_, game, prefix) return storage:list(game, prefix) end,
       delete = function(_, game, key) return storage:delete(game, key) end,
     },

src/mods/Schemas.lua

@@ -1017,6 +1017,9 @@ R.trainers = {
     index = f.opt(f.int(0, 255)),
     -- unused vanilla classes ship without a pic, so it cannot be required
     pic = f.opt(f.path),
+    -- Full-color portrait: skip the 4-shade SGB/GBC remap, same flag pokemon
+    -- and sprites already carry.
+    trueColor = f.opt(f.bool),
     -- Optional Advanced-mode OBJ palette source for a custom trainer portrait.
     -- It follows the same ROM crosswalk form as sprites.paletteSource.
     paletteSource = f.opt(f.str),
@@ -1068,6 +1071,11 @@ R.trainers = {
   gen2Fields = {
     id = f.opt(f.str), name = f.str,
     index = f.opt(f.int(0, 255)),
+    -- class frontpic; when set, this wins over menu_gfx.battleHud.trainerPics
+    pic = f.opt(f.path),
+    -- Full-color portrait: skip the GBC 4-shade remap, same flag Gen 1
+    -- trainers and pokemon already carry.
+    trueColor = f.opt(f.bool),
     baseMoney = f.opt(f.int(0)),
     -- the class's battle theme; Gen 1 spells the same idea `battleTheme`,
     -- but this is the extractor's own key and a strict rename would reject

src/mods/Storage.lua

@@ -1,4 +1,5 @@
--- Data-only per-mod persistence, scoped by game version and opaque playthrough.
+-- Data-only and opaque-byte per-mod persistence, scoped by game version and
+-- opaque playthrough.
 -- This module is engine-private; Loader exposes only the bound facade methods.
 
 local SaveData = require("src.core.SaveData")
@@ -7,6 +8,7 @@ local Version = require("src.core.Version")
 
 local Storage = {}
 Storage.__index = Storage
+Storage.MAX_BYTES = 512 * 1024 * 1024
 
 local ROOT = "mod_storage"
 
@@ -49,6 +51,20 @@ local function decodeAt(fs, path)
   return data, body
 end
 
+local function readOpaqueAt(fs, path)
+  if not (fs.getInfo and fs.getInfo(path)) then return nil end
+  local body = fs.read and fs.read(path)
+  if type(body) ~= "string" then return nil end
+  return body
+end
+
+local function hasAny(fs, paths)
+  for _, path in ipairs(paths) do
+    if fs.getInfo(path) then return true end
+  end
+  return false
+end
+
 function Storage.new(modId, fs)
   assert(validSegment(modId), "Storage.new needs a safe mod id")
   return setmetatable({ modId = modId, injectedFs = fs }, Storage)
@@ -132,6 +148,10 @@ function Storage:selected(game)
     end,
     read = function(_, key) return self:read(selectedGame, key) end,
     write = function(_, key, value) return self:write(selectedGame, key, value) end,
+    readBytes = function(_, key) return self:readBytes(selectedGame, key) end,
+    writeBytes = function(_, key, bytes)
+      return self:writeBytes(selectedGame, key, bytes)
+    end,
     list = function(_, prefix) return self:list(selectedGame, prefix) end,
     delete = function(_, key) return self:delete(selectedGame, key) end,
   }
@@ -147,7 +167,7 @@ function Storage:context(game)
   }
 end
 
-function Storage:_names(game, key, allowEmpty)
+function Storage:_names(game, key, allowEmpty, extension)
   if not validKey(key, allowEmpty) then
     return failure("invalid_key",
       "Storage keys use nonempty letters, numbers, underscore, dash and slash segments.")
@@ -155,12 +175,19 @@ function Storage:_names(game, key, allowEmpty)
   local scope, code, message = self:_scope(game)
   if not scope then return nil, code, message end
   local path = scope.base .. (key ~= "" and ("/" .. key) or "")
-  return scope, path .. ".lua", path .. ".lua.bak", path .. ".lua.tmp"
+  extension = extension or ".lua"
+  return scope, path .. extension, path .. extension .. ".bak",
+    path .. extension .. ".tmp", path
 end
 
 function Storage:write(game, key, value)
-  local scope, main, bak, tmp = self:_names(game, key, false)
+  local scope, main, bak, tmp, path = self:_names(game, key, false)
   if not scope then return false, main, bak end
+  local fs = scope.fs
+  if hasAny(fs, { path .. ".bin", path .. ".bin.bak", path .. ".bin.tmp" }) then
+    return false, "type_conflict",
+      "A byte value already exists for this storage key; delete it first."
+  end
   if type(value) ~= "table" then
     return false, "encode_failed", "Storage values must be data-only tables."
   end
@@ -170,7 +197,6 @@ function Storage:write(game, key, value)
       .. tostring(encoded)
   end
 
-  local fs = scope.fs
   ensureParent(fs, main)
   local _, previous = decodeAt(fs, main)
   if not previous then _, previous = decodeAt(fs, bak) end
@@ -206,9 +232,13 @@ function Storage:write(game, key, value)
 end
 
 function Storage:read(game, key)
-  local scope, main, bak, tmp = self:_names(game, key, false)
+  local scope, main, bak, tmp, path = self:_names(game, key, false)
   if not scope then return nil, main, bak end
   local fs = scope.fs
+  if hasAny(fs, { path .. ".bin", path .. ".bin.bak", path .. ".bin.tmp" }) then
+    return failure("type_mismatch",
+      "This storage key contains opaque bytes; use readBytes instead.")
+  end
   local data, body = decodeAt(fs, main)
   if data then return data end
 
@@ -226,6 +256,80 @@ function Storage:read(game, key)
   return data
 end
 
+function Storage:writeBytes(game, key, bytes)
+  local scope, main, bak, tmp, path = self:_names(game, key, false, ".bin")
+  if not scope then return false, main, bak end
+  if type(bytes) ~= "string" then
+    return false, "invalid_bytes", "Opaque storage values must be strings."
+  end
+  if #bytes > Storage.MAX_BYTES then
+    return false, "size_limit",
+      ("Opaque storage values cannot exceed %d bytes."):format(Storage.MAX_BYTES)
+  end
+
+  local fs = scope.fs
+  if hasAny(fs, { path .. ".lua", path .. ".lua.bak", path .. ".lua.tmp" }) then
+    return false, "type_conflict",
+      "A table value already exists for this storage key; delete it first."
+  end
+
+  ensureParent(fs, main)
+  local previous = readOpaqueAt(fs, main)
+  if previous == nil then previous = readOpaqueAt(fs, bak) end
+
+  local ok, err = fs.write(tmp, bytes)
+  if not ok then
+    return false, "write_failed", "Could not stage opaque storage data: " .. tostring(err)
+  end
+  local staged = readOpaqueAt(fs, tmp)
+  if staged == nil or staged ~= bytes then
+    remove(fs, tmp)
+    return false, "verify_failed", "Staged opaque storage data could not be verified."
+  end
+
+  if previous ~= nil then fs.write(bak, previous) end
+  ok, err = fs.write(main, bytes)
+  if not ok then
+    remove(fs, tmp)
+    return false, "write_failed",
+      "Could not replace opaque storage data: " .. tostring(err)
+  end
+  local verified = readOpaqueAt(fs, main)
+  if verified == nil or verified ~= bytes then
+    remove(fs, main)
+    remove(fs, tmp)
+    return false, "verify_failed",
+      "Replacement opaque storage data could not be verified."
+  end
+
+  fs.write(bak, bytes)
+  remove(fs, tmp)
+  return true
+end
+
+function Storage:readBytes(game, key)
+  local scope, main, bak, tmp, path = self:_names(game, key, false, ".bin")
+  if not scope then return nil, main, bak end
+  local fs = scope.fs
+  if hasAny(fs, { path .. ".lua", path .. ".lua.bak", path .. ".lua.tmp" }) then
+    return failure("type_mismatch",
+      "This storage key contains table data; use read instead.")
+  end
+
+  local bytes = readOpaqueAt(fs, main)
+  if bytes ~= nil then return bytes end
+  bytes = readOpaqueAt(fs, tmp)
+  if bytes == nil then bytes = readOpaqueAt(fs, bak) end
+  if bytes == nil then
+    return nil, "not_found", "No valid opaque value exists for this key."
+  end
+
+  ensureParent(fs, main)
+  if fs.write(main, bytes) then fs.write(bak, bytes) end
+  remove(fs, tmp)
+  return bytes
+end
+
 function Storage:list(game, prefix)
   prefix = prefix or ""
   local scope, main, codeOrBak = self:_names(game, prefix, true)
@@ -237,13 +341,23 @@ function Storage:list(game, prefix)
 
   local base = scope.base
   local start = prefix == "" and base or (base .. "/" .. prefix)
-  local out = {}
+  local out, seen = {}, {}
+
+  local function add(logical)
+    if not seen[logical] then
+      seen[logical] = true
+      out[#out + 1] = logical
+    end
+  end
 
   local function walk(path, logical)
     local info = fs.getInfo(path)
     if not info then return end
     if info.type == "file" then
-      if path:sub(-4) == ".lua" then out[#out + 1] = logical:sub(1, -5) end
+      local suffix = path:sub(-4)
+      if suffix == ".lua" or suffix == ".bin" then
+        add(logical:sub(1, -5))
+      end
       return
     end
     for _, child in ipairs(fs.getDirectoryItems(path) or {}) do
@@ -254,7 +368,9 @@ function Storage:list(game, prefix)
 
   -- A prefix may identify one exact key or a directory of keys.
   if fs.getInfo(start .. ".lua") then
-    out[#out + 1] = prefix
+    add(prefix)
+  elseif fs.getInfo(start .. ".bin") then
+    add(prefix)
   else
     walk(start, prefix)
   end
@@ -263,15 +379,20 @@ function Storage:list(game, prefix)
 end
 
 function Storage:delete(game, key)
-  local scope, main, bak, tmp = self:_names(game, key, false)
+  local scope, main, bak, tmp, path = self:_names(game, key, false)
   if not scope then return false, main, bak end
   local fs = scope.fs
-  if not (fs.getInfo(main) or fs.getInfo(bak) or fs.getInfo(tmp)) then
+  local byteMain, byteBak, byteTmp = path .. ".bin", path .. ".bin.bak", path .. ".bin.tmp"
+  if not (fs.getInfo(main) or fs.getInfo(bak) or fs.getInfo(tmp)
+      or fs.getInfo(byteMain) or fs.getInfo(byteBak) or fs.getInfo(byteTmp)) then
     return false, "not_found", "No stored value exists for this key."
   end
   remove(fs, main)
   remove(fs, bak)
   remove(fs, tmp)
+  remove(fs, byteMain)
+  remove(fs, byteBak)
+  remove(fs, byteTmp)
   return true
 end
 

src/ui/BagMenu.lua

@@ -383,6 +383,7 @@ local function pickTargetAndUse(game, battle, id, list)
   local def = game.data.items[id]
   local opts = {
     pickOnly = true,
+    battle = battle,
     -- HP medicine animates its bar with the picker still up (#252).  Only
     -- out of battle: the in-battle tail closes the bag list underneath
     -- first, which needs the picker already gone.

src/ui/OakSpeech.lua

@@ -98,14 +98,14 @@ function OakSpeech.resolvePic(game, desc, speech)
   local t = desc.type
   if t == "trainer" then
     if speech and desc.id == "OPP_PROF_OAK" and speech.oakPic then
-      return speech.oakPic, false, false
+      return speech.oakPic, false, speech.oakTrueColor or false
     end
     if speech and desc.id == "OPP_RIVAL1" and speech.rivalPic then
-      return speech.rivalPic, false, false
+      return speech.rivalPic, false, speech.rivalTrueColor or false
     end
     local trainers = game.data.trainers or {}
     local tr = trainers[desc.id]
-    return tryImage(tr and tr.pic), false, false
+    return tryImage(tr and tr.pic), false, tr and tr.trueColor or false
   elseif t == "pokemon" then
     if speech and desc.id == speech.demoSpecies and speech.demoPic then
       return speech.demoPic, desc.flip and true or false, speech.demoTrueColor
@@ -241,7 +241,11 @@ function OakSpeech.new(game, onDone)
   self.answers = {}
   local trainers = game.data.trainers or {}
   self.oakPic = tryImage(trainers.OPP_PROF_OAK and trainers.OPP_PROF_OAK.pic)
+  self.oakTrueColor = self.oakPic
+    and trainers.OPP_PROF_OAK and trainers.OPP_PROF_OAK.trueColor or false
   self.rivalPic = tryImage(trainers.OPP_RIVAL1 and trainers.OPP_RIVAL1.pic)
+  self.rivalTrueColor = self.rivalPic
+    and trainers.OPP_RIVAL1 and trainers.OPP_RIVAL1.trueColor or false
   local oakGfx = (game.data.field and game.data.field.oakSpeech) or {}
   self.cfg = oakGfx
   -- the show-off mon and the name length cap come from data; the vanilla

src/ui/PartyMenu.lua

@@ -289,6 +289,7 @@ function PartyMenu.new(game, opts)
   opts = opts or {}
   local self = setmetatable({}, PartyMenu)
   self.game = game
+  local party = opts.party or (opts.battle and opts.battle.playerParty)
   -- PartyMenuInit (home/pokemon.asm) seeds the cursor from
   -- wPartyAndBillsPCSavedMenuItem rather than from zero, and
   -- HandlePartyMenuInput writes wCurrentMenuItem back into it on every
@@ -297,7 +298,7 @@ function PartyMenu.new(game, opts)
   -- both zero the byte, which BattleState mirrors.  The clamp covers a
   -- party that shrank (deposit / release) while the saved index was
   -- pointing past the end. #768
-  local count = #(opts.party or (game.save and game.save.party) or {})
+  local count = #(party or (game.save and game.save.party) or {})
   self.index = math.min(math.max(1, game.partyMenuSavedIndex or 1),
                         math.max(1, count))
   self.onSwitch = opts.onSwitch
@@ -314,7 +315,7 @@ function PartyMenu.new(game, opts)
   self.tmhm = opts.tmhm
   self.forceSwitch = opts.forceSwitch
   self.battle = opts.battle
-  self.party = opts.party -- link battles pass their clamped copies
+  self.party = party -- link/scoped battles pass their local party view
   self.swapFrom = nil
   self.submenu = nil
   self.subIndex = 1

src/ui/gen2/BattleState.lua

@@ -185,6 +185,19 @@ function BattleState:statusHUDVisible()
                       self) ~= false
 end
 
+-- Class frontpic for the battle intro.  A trainers-registry `pic` wins over
+-- the extracted menu_gfx sheet; `trueColor` skips the GBC 4-shade remap.
+-- Returns path, trueColor.
+function BattleState.trainerArt(data, classId)
+  if not classId then return nil, false end
+  local classes = data and data.gen2Trainers and data.gen2Trainers.classes
+  local classDef = classes and classes[classId]
+  local hud = data and data.gen2MenuGfx and data.gen2MenuGfx.battleHud
+  local path = (classDef and classDef.pic)
+    or (hud and hud.trainerPics and hud.trainerPics[classId])
+  return path, (classDef and classDef.trueColor) and true or false
+end
+
 -- opts: battle (a Battle), onDone(outcome), save
 function BattleState.new(game, opts)
   opts = opts or {}
@@ -308,6 +321,7 @@ function BattleState.new(game, opts)
   -- pic is a cache asset, so an import made before the extractor grew that
   -- stage has none and the mon stands in for the whole intro.
   self.showEnemyTrainer = false
+  self.enemyTrainerTrueColor = false
   -- The CLASS CONSTANT (BUG_CATCHER), which is what both tables this looks the
   -- pic up in are keyed by: menu_gfx's trainerPics is written out of
   -- constants.trainerClassOrder, and palettes.trainers out of the same names.
@@ -317,17 +331,19 @@ function BattleState.new(game, opts)
   -- no palette for every trainer the world starts, which is all of them.
   -- `classId` is the trainers.lua key, i.e. the constant; `className` is the
   -- DISPLAY name ("BUG CATCHER", with the space) and is not a key at all.
+  -- A class record's own `pic` / `trueColor` (the trainers registry) wins
+  -- over the extracted sheet, so a mod can drop in full-color art.
   local enemyTrainer = self.battle and self.battle.trainer
   self.enemyTrainerClass = enemyTrainer
     and (enemyTrainer.classId or enemyTrainer.class)
-  local trainerPics = hudGfx and hudGfx.trainerPics
-  local trainerPath = self.enemyTrainerClass and trainerPics
-    and trainerPics[self.enemyTrainerClass]
+  local trainerPath, trainerTrueColor =
+    BattleState.trainerArt(data, self.enemyTrainerClass)
   if trainerPath then
     local ok, image = pcall(Assets.image, trainerPath)
     if ok and image then
       self.enemyTrainerImage = image
       self.enemyTrainerPath = trainerPath
+      self.enemyTrainerTrueColor = trainerTrueColor and true or false
       self.showEnemyTrainer = true
     end
   end
@@ -588,7 +604,10 @@ function BattleState:drawPic(mon, back)
   -- slides it out (InitEnemyTrainer, engine/battle/core.asm:7848).
   local enemyTrainer = (not back) and self.showEnemyTrainer
     and self.enemyTrainerImage
-  if enemyTrainer then image, path = enemyTrainer, self.enemyTrainerPath end
+  if enemyTrainer then
+    image, path = enemyTrainer, self.enemyTrainerPath
+    trueColor = self.enemyTrainerTrueColor
+  end
   if not image then return end
   local side = back and "player" or "enemy"
   local anim = self:animPicState(side)

src/world/OverworldController.lua

@@ -230,6 +230,7 @@ function OverworldState:enter(mapId, x, y, facing, opts)
   -- a fresh entry, or a stale flag can freeze player input forever
   self.engaging = false
   self.emote = nil
+  self.cancelledTrainerSight = nil
   -- volatile WRAM state in pokered; never serialize across save/load
   self.wildEncounterGraceSteps = 0
   -- survives save/load: a loaded game may start inside a building whose
@@ -762,6 +763,27 @@ function OverworldState:bikeAllowed(mapId)
   return false
 end
 
+-- Field-item entry points keep presentation and state transitions in the
+-- owning world instead of asking a supported facade to reproduce either one.
+function OverworldState:useBicycle()
+  local name = Game.save.player.name
+  if Game.save.onBike then
+    if Game.save.forcedBike then return false end
+    Game.save.onBike = false
+    require("src.core.Music").playMap(Game.data, self.map.id, false)
+    Game.stack:push(TextBox.new(Game,
+      Strings("%s got off\nthe BICYCLE.", name)))
+  elseif self:bikeAllowed(self.map.id) and not self.player.surfing then
+    Game.save.onBike = true
+    require("src.core.Music").playMap(Game.data, self.map.id, true)
+    Game.stack:push(TextBox.new(Game,
+      Strings("%s got on\nthe BICYCLE!", name)))
+  else
+    return false
+  end
+  return true
+end
+
 -- The battle transition's dungeon wipe uses the explicit map lists in
 -- data/maps/dungeon_maps.asm (field.dungeonTransitionMaps): singles plus
 -- inclusive map-id ranges -- faithful to the original's omissions
@@ -1725,6 +1747,12 @@ function OverworldState:goFishing(rod)
   end))
 end
 
+function OverworldState:useFishingRod(rod)
+  if self.player.surfing or not self:facingIsShoreOrWater() then return false end
+  self:goFishing(rod)
+  return true
+end
+
 -- Fly to a visited town (called from the party menu).
 function OverworldState:flyTo(mapId)
   local spot = Game.data.field.flyWarps[mapId]
@@ -3092,6 +3120,32 @@ local function meetTrainerTheme(cls)
          or "Music_MeetMaleTrainer"
 end
 
+-- Public pre-trainer gate. A mod may retain continueBattle while a registered
+-- preparation screen is on top, then resume once with an optional ordered
+-- save-party index scope. The hook is cold on a no-mod boot.
+function OverworldState.prepareTrainerBattle(game, context, startBattle,
+    cancelBattle)
+  if not Runtime.wantsHook("trainer.before_battle") then
+    startBattle()
+    return false
+  end
+  local started = false
+  local function continueBattle(options)
+    if started then return false end
+    started = true
+    if type(options) == "table" and options.cancel == true then
+      if cancelBattle then cancelBattle() end
+    else
+      startBattle(options)
+    end
+    return true
+  end
+  local deferred = Runtime.call("trainer.before_battle",
+    function() return false end, game, context, continueBattle)
+  if deferred ~= true and not started then continueBattle() end
+  return deferred == true
+end
+
 -- Run the pre-battle text -> battle -> won text -> flags sequence.
 -- skipBattleText is for map scripts shaped like SilphCo11FDefaultScript
 -- (scripts/SilphCo11F.asm), which DisplayTextID the challenge line BEFORE
@@ -3119,7 +3173,8 @@ function OverworldState:engageTrainer(npc, onDone, endBattleText, skipBattleText
                   or (header and header.won and Game.data.text[header.won])
 
   local BattleState = require("src.battle.BattleState")
-  local function startBattle()
+  local function startBattle(options)
+    self.cancelledTrainerSight = nil
     -- TalkToTrainer (home/trainers.asm:88) prints the before-battle text
     -- FIRST and only then runs `call EngageMapTrainer` / `jp
     -- StartTrainerBattle`, so a trainer challenged on foot gets the sting
@@ -3134,7 +3189,8 @@ function OverworldState:engageTrainer(npc, onDone, endBattleText, skipBattleText
       local theme = meetTrainerTheme(d.trainerClass)
       if theme then require("src.core.Music").play(Game.data, theme) end
     end
-    local battle = BattleState.newTrainer(Game, d.trainerClass, d.trainerParty)
+    local battle = BattleState.newTrainer(Game, d.trainerClass, d.trainerParty,
+      options)
     battle.checkpointOrigin = {
       kind = "trainer_encounter",
       map = self.map.id,
@@ -3171,10 +3227,31 @@ function OverworldState:engageTrainer(npc, onDone, endBattleText, skipBattleText
     end
     self:pushBattle(battle)
   end
+  local function prepareBattle()
+    if not Runtime.wantsHook("trainer.before_battle") then
+      startBattle()
+      return
+    end
+    OverworldState.prepareTrainerBattle(Game, {
+      trainerClass = d.trainerClass,
+      partyIndex = d.trainerParty or 1,
+      mapId = self.map.id,
+      npcId = npc.id,
+    }, startBattle, function()
+      if self.player then
+        self.cancelledTrainerSight = {
+          npcId = npc.id,
+          playerX = self.player.cellX,
+          playerY = self.player.cellY,
+        }
+      end
+      if onDone then onDone() end
+    end)
+  end
   if skipBattleText then
-    startBattle()
+    prepareBattle()
   else
-    Game.stack:push(TextBox.new(Game, battleText, startBattle))
+    Game.stack:push(TextBox.new(Game, battleText, prepareBattle))
   end
 end
 
@@ -3372,11 +3449,18 @@ function OverworldState:checkTrainerSight()
   if self.player.moving or self.engaging then return end
   if Game.stack:top() ~= self then return end
   local p = self.player
+  local cancelled = self.cancelledTrainerSight
+  if cancelled and (cancelled.playerX ~= p.cellX
+      or cancelled.playerY ~= p.cellY) then
+    self.cancelledTrainerSight = nil
+    cancelled = nil
+  end
   for _, npc in ipairs(self.npcs) do
     local d = npc.def
     -- CheckFightingMapTrainers engages ANY aligned trainer sprite,
     -- walkers included (they sight between steps)
     if d.trainerClass and not npc.moving
+       and not (cancelled and cancelled.npcId == npc.id)
        and not self:trainerDefeated(npc)
        and not mapScripts.talkScript(self.map.id, d.text)
        and trainerSpriteOnScreen(npc, p) then

src/world/WorldAPI.lua

@@ -15,6 +15,7 @@ local WorldAPI = {}
 WorldAPI.__index = WorldAPI
 
 local NO_OVERWORLD = "no overworld"
+local RODS = { "OLD_ROD", "GOOD_ROD", "SUPER_ROD" }
 
 local function acceptsMenuInput(game, ow)
   local stack = game and game.stack
@@ -86,6 +87,60 @@ function WorldAPI:reorderParty(fromSlot, toSlot)
   return true
 end
 
+-- Contextual field-item shortcuts. Only actions that can start immediately
+-- are listed; callers receive copied labels and never inspect world internals.
+function WorldAPI:availableFieldActions()
+  local game, ow, out = self.game, self:overworld(), {}
+  if not (game and game.save and ow and ow.map and ow.player)
+      or not acceptsMenuInput(game, ow) then return out end
+  local save, inventory = game.save, game.save.inventory or {}
+  local items = game.data and game.data.items or {}
+
+  if (inventory.BICYCLE or 0) > 0 and not ow.player.surfing
+      and not (save.onBike and save.forcedBike)
+      and (save.onBike or ow:bikeAllowed(ow.map.id)) then
+    out[#out + 1] = { id = "bicycle",
+      label = save.onBike and "BIKE OFF" or "BICYCLE" }
+  end
+
+  if not ow.player.surfing and ow:facingIsShoreOrWater() then
+    local rods = {}
+    for _, id in ipairs(RODS) do
+      if (inventory[id] or 0) > 0 then
+        local def = items[id]
+        rods[#rods + 1] = { id = id, label = def and def.name or id }
+      end
+    end
+    if #rods > 0 then
+      out[#out + 1] = { id = "fish", label = "FISH", rods = rods }
+    end
+  end
+  return out
+end
+
+function WorldAPI:useFieldAction(id, opts)
+  local game, ow = self.game, self:overworld()
+  if not ow then return nil, NO_OVERWORLD end
+  if not acceptsMenuInput(game, ow) then return nil, "world is busy" end
+  local found
+  for _, action in ipairs(self:availableFieldActions()) do
+    if action.id == id then found = action break end
+  end
+  if not found then return nil, "field action unavailable" end
+
+  if id == "bicycle" then
+    if ow:useBicycle() then return true end
+  elseif id == "fish" then
+    local rod = opts and opts.rod
+    if not rod and #found.rods == 1 then rod = found.rods[1].id end
+    for _, choice in ipairs(found.rods) do
+      if choice.id == rod and ow:useFishingRod(rod) then return true end
+    end
+    return nil, "fishing rod unavailable"
+  end
+  return nil, "field action unavailable"
+end
+
 -- A compact, read-only view of the active map for minimaps and companion UIs.
 -- `rows` describes collision terrain; optional `tileRows` reduces each real
 -- 8x8 map tile to its average Game Boy shade ("0" lightest, "3" darkest).

src/world/gen2/WorldAPI.lua

@@ -27,11 +27,15 @@ local Movement = require("src.script.gen2.Movement")
 local Runtime = require("src.mods.Runtime")
 local HiddenItems = require("src.world.gen2.HiddenItems")
 local MapOverview = require("src.world.MapOverview")
+local Bike = require("src.world.gen2.Bike")
+local FieldMoves = require("src.world.gen2.FieldMoves")
+local Permissions = require("src.world.gen2.Permissions")
 
 local WorldAPI = {}
 WorldAPI.__index = WorldAPI
 
 local NO_OVERWORLD = "no overworld"
+local RODS = { "OLD_ROD", "GOOD_ROD", "SUPER_ROD" }
 
 function WorldAPI.new(game, modId)
   return setmetatable({ game = game, modId = modId }, WorldAPI)
@@ -52,6 +56,77 @@ function WorldAPI:current()
            facing = p and p.facing }
 end
 
+local function itemLabel(game, id)
+  local def = game and game.data and game.data.items
+    and game.data.items[id]
+  return (def and def.name) or id
+end
+
+-- The same field-item contract as Gen 1, resolved through Gold's own bike,
+-- collision and fishing rules.
+function WorldAPI:availableFieldActions()
+  local world, game, out = self:overworld(), self.game, {}
+  if not (world and game and game.save and world.map and world.player)
+      or not world:acceptsMenuInput() then return out end
+  local inventory = game.save.inventory or {}
+
+  if (inventory.BICYCLE or 0) > 0 then
+    local bike = Bike.tryBike({
+      state = world.playerState,
+      environment = world.map.def and world.map.def.environment,
+      collision = world:playerCollision(),
+      alwaysOnBike = world:alwaysOnBike(),
+    })
+    if bike == "mount" or bike == "dismount" then
+      out[#out + 1] = { id = "bicycle",
+        label = bike == "dismount" and "BIKE OFF" or "BICYCLE" }
+    end
+  end
+
+  local context = world:fieldContext()
+  if not FieldMoves.isSurfing(world.playerState)
+      and Permissions.isWater(context.facingColl) then
+    local rods = {}
+    for _, id in ipairs(RODS) do
+      if (inventory[id] or 0) > 0 then
+        rods[#rods + 1] = { id = id, label = itemLabel(game, id) }
+      end
+    end
+    if #rods > 0 then
+      out[#out + 1] = { id = "fish", label = "FISH", rods = rods }
+    end
+  end
+  return out
+end
+
+function WorldAPI:useFieldAction(id, opts)
+  local world = self:overworld()
+  if not world then return nil, NO_OVERWORLD end
+  if not world:acceptsMenuInput() then return nil, "world is busy" end
+  local found
+  for _, action in ipairs(self:availableFieldActions()) do
+    if action.id == id then found = action break end
+  end
+  if not found then return nil, "field action unavailable" end
+
+  if id == "bicycle" then
+    local outcome = world:useFieldItem("BICYCLE")
+    if outcome and outcome ~= "nowhere" then return true end
+  elseif id == "fish" then
+    local rod = opts and opts.rod
+    if not rod and #found.rods == 1 then rod = found.rods[1].id end
+    for _, choice in ipairs(found.rods) do
+      if choice.id == rod then
+        local outcome = world:useFieldItem(rod)
+        if outcome and outcome ~= "nowhere" then return true end
+        break
+      end
+    end
+    return nil, "fishing rod unavailable"
+  end
+  return nil, "field action unavailable"
+end
+
 -- The same read-only minimap contract as Gen 1, with Gold's object/event
 -- visibility rules supplying the semantic markers.
 function WorldAPI:mapOverview()

tests/drivers/escort_lockstep_test.lua

@@ -0,0 +1,40 @@
+-- Driver: Oak's Pallet Town escort.  Logs the player/Oak separation the
+-- whole way down and shoots the walk mid-street, so the formation is
+-- checkable by eye as well as by number (the escort holds one cell,
+-- ~16px; a desynced Oak drifts off by a cell per two steps).
+return function(game)
+  local U = dofile("tests/drivers/util.lua")
+  local DIR = os.getenv("SHOT_DIR") or "/tmp/shots"
+  U.teleport(game, "PALLET_TOWN", 10, 3, "up")
+  local ow = game.overworld
+  local function oak()
+    for _, n in ipairs(ow.npcs or {}) do
+      if n.def and n.def.name == "PALLETTOWN_OAK" then return n end
+    end
+  end
+  U.hold(game, "up", 40)
+  local worst, samples = 0, 0
+  for _ = 1, 1200 do
+    if game.stack:top() ~= ow then U.tap(game, "a") end
+    local o = oak()
+    if o and #ow.scriptMoves > 0 and ow.map.id == "PALLET_TOWN" then
+      local d = math.abs(o.px - ow.player.px) + math.abs(o.py - ow.player.py)
+      if samples > 0 or d <= 20 then
+        samples = samples + 1
+        if d > worst then worst = d end
+        if samples == 60 then U.shot(game, DIR .. "/escort_midwalk.png") end
+        if samples % 24 == 1 then
+          U.log(("t=%d player=(%d,%d) oak=(%d,%d) dist=%dpx")
+            :format(samples, ow.player.cellX, ow.player.cellY,
+                    o.cellX, o.cellY, d))
+        end
+      end
+    end
+    if ow.map.id == "OAKS_LAB" then break end
+    U.wait(2)
+  end
+  U.log(("ESCORT worst separation: %dpx over %d samples"):format(worst, samples))
+  U.log("map:", ow.map.id, "flag:",
+        tostring(game.save.flags.EVENT_FOLLOWED_OAK_INTO_LAB))
+  love.event.quit()
+end

tests/engine/trainer_battle_party_scope.lua

@@ -0,0 +1,131 @@
+-- Trainer battles may use a battle-local view of save-party records without
+-- mutating, reordering, or hiding those records in the authoritative save.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+love = love or require("tests.love_stub")
+
+local T = require("tests.harness").suite("trainer battle party scope")
+local BattleState = require("src.battle.BattleState")
+local BagMenu = require("src.ui.BagMenu")
+local Fixtures = require("tests.modkit").fixtures
+local PartyMenu = require("src.ui.PartyMenu")
+local Pokemon = require("src.pokemon.Pokemon")
+local SaveData = require("src.core.SaveData")
+local Bag = require("src.inventory.Bag")
+
+local Data = Fixtures.fresh()
+Data.items.POTION = { id = "POTION", index = 99, name = "POTION",
+  price = 300, tossable = true }
+
+local function makeGame()
+  local save = SaveData.newGame()
+  save.party = {
+    Pokemon.new(Data, "FIXMON_A", 10),
+    Pokemon.new(Data, "FIXMON_B", 11),
+    Pokemon.new(Data, "FIXMON_C", 12),
+  }
+  local stack = { states = {} }
+  function stack:push(value) self.states[#self.states + 1] = value end
+  function stack:pop() return table.remove(self.states) end
+  function stack:top() return self.states[#self.states] end
+  return { data = Data, save = save, stack = stack }
+end
+
+local game = makeGame()
+local originalParty = game.save.party
+local first, second, third = unpack(originalParty)
+local battle = BattleState.newTrainer(game, "OPP_FIX_YOUNGSTER", 1, {
+  playerPartyIndices = { 2, 3 },
+})
+T.check(game.save.party == originalParty,
+  "scoping never replaces the authoritative save-party table")
+T.check(game.save.party[1] == first and game.save.party[2] == second
+    and game.save.party[3] == third,
+  "scoping never reorders authoritative save-party records")
+T.same(battle.playerPartyIndices, { 2, 3 },
+  "the battle records normalized save-party indices")
+T.check(battle.playerParty[1] == second and battle.playerParty[2] == third,
+  "the local party view contains the same selected Pokemon records")
+T.check(battle.player.mon == second,
+  "initial send chooses the first healthy scoped member")
+
+local menu = PartyMenu.new(game, { battle = battle })
+T.check(menu.party == battle.playerParty,
+  "battle party menus traverse only the local eligible view")
+
+Bag.add(game.save, "POTION", 1)
+local bag = BagMenu.new(game, { battle = battle })
+local potion
+for _, row in ipairs(bag.items) do
+  if row.value == "POTION" then potion = row; break end
+end
+T.check(potion ~= nil, "the fixture potion is available for target selection")
+bag.onChoose(potion, bag)
+local targetPicker = game.stack:top()
+T.check(targetPicker and targetPicker.party == battle.playerParty,
+  "in-battle item target selection traverses only eligible members")
+
+second.hp = 0
+battle.player.mon.hp = 0
+battle:playerMonFainted()
+T.eq(battle.result, nil,
+  "a healthy scoped replacement prevents premature exhaustion")
+third.hp = 0
+battle:playerMonFainted()
+T.eq(battle.result, "lose",
+  "an excluded healthy save-party member cannot prevent scoped exhaustion")
+T.check(first.hp > 0, "the excluded save-party member remains untouched")
+
+local expGame = makeGame()
+expGame.save.inventory.EXP_ALL = 1
+local expBattle = BattleState.newTrainer(expGame,
+  "OPP_FIX_YOUNGSTER", 1, { playerPartyIndices = { 2, 3 } })
+local excludedExp = expGame.save.party[1].exp
+local participantExp = expGame.save.party[2].exp
+local sharedExp = expGame.save.party[3].exp
+expBattle.participants = { [expGame.save.party[2]] = true }
+expBattle:awardExp()
+T.eq(expGame.save.party[1].exp, excludedExp,
+  "EXP.ALL cannot award an excluded save-party member")
+T.check(expGame.save.party[2].exp > participantExp,
+  "a scoped participant receives battle experience")
+T.check(expGame.save.party[3].exp > sharedExp,
+  "EXP.ALL traverses other eligible scoped members")
+
+local fallbackGame = makeGame()
+local fallback = BattleState.newTrainer(fallbackGame,
+  "OPP_FIX_YOUNGSTER", 1, { playerPartyIndices = { 0, 99, 1.5, 0 } })
+T.eq(fallback.playerParty, nil,
+  "a malformed or empty scope degrades to the vanilla full-party path")
+T.eq(fallback.player.mon, fallbackGame.save.party[1],
+  "invalid scope fallback preserves vanilla initial send")
+
+local partialGame = makeGame()
+local partial = BattleState.newTrainer(partialGame,
+  "OPP_FIX_YOUNGSTER", 1, { playerPartyIndices = { 2, 99 } })
+T.eq(partial.playerParty, nil,
+  "one invalid member makes the entire scope fall back")
+
+local duplicateGame = makeGame()
+local duplicate = BattleState.newTrainer(duplicateGame,
+  "OPP_FIX_YOUNGSTER", 1, { playerPartyIndices = { 2, 2 } })
+T.eq(duplicate.playerParty, nil,
+  "duplicate members make the entire scope fall back")
+
+local malformedOptionsGame = makeGame()
+local malformedOptions = BattleState.newTrainer(malformedOptionsGame,
+  "OPP_FIX_YOUNGSTER", 1, 7)
+T.eq(malformedOptions.playerParty, nil,
+  "a malformed options value degrades to the vanilla full-party path")
+
+local linkGame = makeGame()
+local linkBattle = BattleState.newTrainer(linkGame,
+  "OPP_FIX_YOUNGSTER", 1, { playerPartyIndices = { 2, 3 } })
+linkBattle.kind = "link"
+linkBattle.result = "guestWin"
+linkGame.save.party[2].hp, linkGame.save.party[3].hp = 0, 0
+linkBattle:finish()
+T.eq(linkBattle.result, "guestWin",
+  "link spectator outcomes are not rewritten by trainer eligibility scope")
+
+T.finish()

tests/engine/trainer_talk_sting_bug764.lua

@@ -13,6 +13,8 @@ package.path = "./?.lua;./?/init.lua;" .. package.path
 
 local T = require("tests.modkit")
 local OW = require("src.world.OverworldController")
+local Hooks = require("src.mods.Hooks")
+local Runtime = require("src.mods.Runtime")
 
 local function setUpvalue(fn, name, val)
   local i = 1
@@ -96,6 +98,89 @@ T.eq(rivalCount, 0, "rival classes play no encounter sting here")
 local _, seenCount = stingFor("OPP_LASS", true)
 T.eq(seenCount, 0, "self.engaging suppresses a second sting")
 
+-- A deferred preparation may cancel instead of constructing a battle. For a
+-- sight trainer, that must leave a one-position latch: otherwise the still
+-- undefeated adjacent trainer sees the stationary player again next frame and
+-- immediately reopens the preparation screen.
+local oldEvents, oldHooks, oldErrors = Runtime.events, Runtime.hooks,
+  Runtime.errors
+local cancelHooks = Hooks.new()
+Runtime.install(oldEvents, cancelHooks, oldErrors)
+cancelHooks:wrap("trainer.before_battle", function(_, _, _, continue)
+  continue({ cancel = true })
+  return true
+end, 0, "cancel_probe")
+local cancelNpc = { id = "npc#cancel", cellX = 0, cellY = -1,
+  facing = "down", moving = false, def = { trainerClass = "OPP_LASS",
+    trainerParty = 1, index = 1 } }
+fakeSelf.player = { cellX = 0, cellY = 0, moving = false }
+fakeSelf.map.id = "FIX_ROUTE"
+fakeSelf.engaging = false
+pushed, plays = {}, {}
+local completed = 0
+fakeSelf:engageTrainer(cancelNpc, function() completed = completed + 1 end)
+pushed[1].onDone()
+T.eq(completed, 1, "cancel completes the deferred encounter without a battle")
+T.same(fakeSelf.cancelledTrainerSight, {
+  npcId = "npc#cancel", playerX = 0, playerY = 0,
+}, "cancel suppresses immediate sight re-entry at the current player cell")
+
+local approaches = 0
+fakeSelf.npcs = { cancelNpc }
+fakeSelf.trainerDefeated = function() return false end
+fakeSelf.startTrainerApproach = function() approaches = approaches + 1 end
+fakeGame.stack.top = function() return fakeSelf end
+fakeGame.data.trainerHeader = function() return { range = 2 } end
+T.check(setUpvalue(OW.checkTrainerSight, "mapScripts", {
+  talkScript = function() return nil end,
+}), "mapScripts upvalue on checkTrainerSight")
+fakeSelf:checkTrainerSight()
+T.eq(approaches, 0,
+  "a cancelled adjacent trainer cannot reacquire the stationary player")
+fakeSelf.player.cellX = 1
+fakeSelf:checkTrainerSight()
+T.eq(fakeSelf.cancelledTrainerSight, nil,
+  "moving one cell releases the cancelled sight latch")
+fakeSelf.player.cellX = 0
+fakeSelf:checkTrainerSight()
+T.eq(approaches, 1,
+  "returning to the sight line permits a fresh trainer challenge")
+Runtime.install(oldEvents, oldHooks, oldErrors)
+
+-- OverworldState is a singleton reused by StateStack. A title/load cycle must
+-- clear this volatile latch too, or CONTINUE at the same map and cell inherits
+-- the cancelled sight suppression from the previous session.
+local Camera = require("src.render.Camera")
+local Collision = require("src.world.Collision")
+local Encounter = require("src.world.Encounter")
+local ScriptRunner = require("src.script.ScriptRunner")
+local oldCameraNew, oldCollisionLoad = Camera.new, Collision.load
+local oldEncounterLoad, oldRunnerNew = Encounter.load, ScriptRunner.new
+local oldGameModule = package.loaded["src.core.Game"]
+local oldScriptsModule = package.loaded["data.scripts.init"]
+Camera.new = function() return {} end
+Collision.load = function() end
+Encounter.load = function() end
+ScriptRunner.new = function() return {} end
+package.loaded["src.core.Game"] = {
+  data = {}, save = { lastOutdoor = "FIX_ROUTE" },
+}
+package.loaded["data.scripts.init"] = {}
+local lifecycle = setmetatable({
+  cancelledTrainerSight = {
+    npcId = "FIX_ROUTE_obj_1", playerX = 0, playerY = 0,
+  },
+  setMap = function() end,
+  refreshStandingOnWarp = function() end,
+}, { __index = OW })
+lifecycle:enter("FIX_ROUTE", 0, 0, "down", { via = "boot" })
+T.eq(lifecycle.cancelledTrainerSight, nil,
+  "fresh overworld entry clears a cancelled trainer sight latch")
+Camera.new, Collision.load = oldCameraNew, oldCollisionLoad
+Encounter.load, ScriptRunner.new = oldEncounterLoad, oldRunnerNew
+package.loaded["src.core.Game"] = oldGameModule
+package.loaded["data.scripts.init"] = oldScriptsModule
+
 if realMusic ~= nil then package.loaded["src.core.Music"] = realMusic
 else package.loaded["src.core.Music"] = nil end
 if realBattle ~= nil then package.loaded["src.battle.BattleState"] = realBattle

tests/engine/trainer_true_color.lua

@@ -0,0 +1,92 @@
+-- trainers.trueColor: the same 4-shade opt-out pokemon and sprites already
+-- carry, now on the trainers registry.  ROM-free.
+--   luajit tests/engine/trainer_true_color.lua
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.modkit")
+local BattleState = require("src.battle.BattleState")
+local Gen2Battle = require("src.ui.gen2.BattleState")
+local Schemas = require("src.mods.Schemas")
+local OakSpeech = require("src.ui.OakSpeech")
+
+local spec = Schemas.REGISTRIES.trainers
+T.check(spec.fields.trueColor ~= nil,
+  "Gen 1 trainers schema lists trueColor")
+T.check(Schemas.check(spec, "trainers", "OPP_BROCK",
+                      { trueColor = true }, "patch"),
+  "a trueColor patch validates")
+T.check(not Schemas.check(spec, "trainers", "OPP_BROCK",
+                          { trueColor = "yes" }, "patch"),
+  "trueColor rejects a non-boolean")
+
+local gen2 = Schemas.shapeFor("trainers", spec, 2)
+T.check(gen2.fields.trueColor ~= nil and gen2.fields.pic ~= nil,
+  "Gold trainers schema lists pic and trueColor")
+T.check(Schemas.check(spec, "trainers", "BEAUTY",
+                      { pic = "mods/x/beauty.png", trueColor = true },
+                      "patch", 2),
+  "a Gold pic+trueColor patch validates")
+
+T.eq(BattleState.trainerTrueColor(nil, nil), false,
+  "no trainer is not trueColor")
+T.eq(BattleState.trainerTrueColor(nil, { pic = "a.png" }), false,
+  "a vanilla portrait is not trueColor")
+T.eq(BattleState.trainerTrueColor(nil, { trueColor = true }), true,
+  "the record's own flag wins")
+T.eq(BattleState.trainerTrueColor(nil, { trueColor = false }), false,
+  "explicit false stays false")
+
+local data = {
+  trainers = {
+    BASE = { pic = "base.png", trueColor = true },
+    VANILLA = { pic = "vanilla.png" },
+  },
+}
+T.eq(BattleState.trainerTrueColor(data, { basePic = "BASE" }), true,
+  "a basePic reuse inherits the base flag")
+T.eq(BattleState.trainerTrueColor(data,
+      { basePic = "BASE", trueColor = false }), false,
+  "an explicit false on the subclass beats the base")
+T.eq(BattleState.trainerTrueColor(data, { basePic = "VANILLA" }), false,
+  "reusing a vanilla base stays unshaded-off")
+
+local goldData = {
+  gen2Trainers = {
+    classes = {
+      BEAUTY = { pic = "mods/x/beauty.png", trueColor = true },
+      BUG_CATCHER = {},
+    },
+  },
+  gen2MenuGfx = {
+    battleHud = {
+      trainerPics = {
+        BEAUTY = "assets/generated/trainers/beauty.png",
+        BUG_CATCHER = "assets/generated/trainers/bug_catcher.png",
+      },
+    },
+  },
+}
+local beautyPath, beautyTc = Gen2Battle.trainerArt(goldData, "BEAUTY")
+T.eq(beautyPath, "mods/x/beauty.png",
+  "a class pic wins over the extracted sheet")
+T.eq(beautyTc, true, "and keeps trueColor")
+local bugPath, bugTc = Gen2Battle.trainerArt(goldData, "BUG_CATCHER")
+T.eq(bugPath, "assets/generated/trainers/bug_catcher.png",
+  "a class without pic keeps the extracted sheet")
+T.eq(bugTc, false, "and is not trueColor")
+T.eq(select(1, Gen2Battle.trainerArt(goldData, nil)), nil,
+  "no class is no pic")
+
+local game = {
+  data = {
+    trainers = {
+      OPP_BROCK = { pic = "brock.png", trueColor = true },
+      OPP_PROF_OAK = { pic = "oak.png", trueColor = true },
+    },
+  },
+}
+local _, _, oakTc = OakSpeech.resolvePic(game,
+  { type = "trainer", id = "OPP_BROCK" })
+T.eq(oakTc, true, "OakSpeech reports a trainer record's trueColor")
+
+T.finish("trainer true color")

tests/mod_battle_tests.lua

@@ -23,6 +23,7 @@ local MoveEffects = require("src.battle.MoveEffects")
 local Pokemon = require("src.pokemon.Pokemon")
 local Runtime = require("src.mods.Runtime")
 local SaveData = require("src.core.SaveData")
+local Schemas = require("src.mods.Schemas")
 local Status = require("src.battle.Status")
 local TrainerAI = require("src.battle.TrainerAI")
 local TurnOrder = require("src.battle.TurnOrder")
@@ -346,6 +347,20 @@ do
   check(BattleState.trainerPicPath(Data, { basePic = "OPP_ENGINEER" })
         == Data.trainers.OPP_ENGINEER.pic,
         "a custom trainer can reuse a base trainer portrait by id")
+  check(BattleState.trainerTrueColor(Data, { trueColor = true }) == true,
+        "a trainer record's trueColor flag is readable")
+  check(BattleState.trainerTrueColor(Data, { trueColor = false }) == false,
+        "explicit false stays false")
+  check(BattleState.trainerTrueColor(Data, { basePic = "OPP_ENGINEER" })
+        == false,
+        "a vanilla base portrait is not trueColor")
+  check(Schemas.check(Schemas.REGISTRIES.trainers, "trainers", "OPP_BROCK",
+                      { trueColor = true }, "patch"),
+        "a trueColor trainers patch validates against the catalog schema")
+  check(Schemas.check(Schemas.REGISTRIES.trainers, "trainers", "BEAUTY",
+                      { pic = "mods/x/beauty.png", trueColor = true },
+                      "patch", 2),
+        "a Gold trainers patch can carry pic and trueColor")
 end
 
 do

tests/mod_graphics_tests.lua

@@ -370,6 +370,32 @@ check(math.abs(r - 0.4) < 1e-6 and math.abs(g - 0.7) < 1e-6
       and math.abs(b - 0.9) < 1e-6,
       "a trueColor pic keeps a pixel no 4-shade palette contains")
 
+-- trainers.trueColor is the same opt-out on a class portrait
+BattleState.invalidate()
+local trainerPicData = {
+  trainers = {
+    SHADED = { pic = "assets/generated/battle/front/shaded.png" },
+    FULLCOLOR = { pic = "assets/generated/battle/front/full.png",
+                  trueColor = true },
+    REUSED = { basePic = "FULLCOLOR" },
+  },
+  palettes = { palettes = { MEWMON = monPalette }, pokemon = {} },
+}
+local shadedTrainer = BattleState.trainerSprite(trainerPicData,
+  trainerPicData.trainers.SHADED)
+r, g, b = shadedTrainer.data:getPixel(0, 0)
+check(r == 0 and g == 0 and b == 1,
+      "a 4-shade trainer pic is palette-quantized onto its shade bucket")
+local fullTrainer = BattleState.trainerSprite(trainerPicData,
+  trainerPicData.trainers.FULLCOLOR)
+r, g, b = fullTrainer.data:getPixel(0, 0)
+check(math.abs(r - 0.4) < 1e-6 and math.abs(g - 0.7) < 1e-6
+      and math.abs(b - 0.9) < 1e-6,
+      "a trueColor trainer pic keeps a pixel no 4-shade palette contains")
+check(BattleState.trainerTrueColor(trainerPicData,
+        trainerPicData.trainers.REUSED) == true,
+      "a basePic reuse inherits the base portrait's trueColor flag")
+
 -- ------- trueColor: the colors == false zone sentinel
 
 check(PaletteFX.zone(nil, 0, 0, 1, 1) == nil, "nil colors is still no zone")

tests/modkit/cases/checkpoints.lua

@@ -358,11 +358,13 @@ T.same(checkpoints:capture(game), beforeFailure,
 -- The same public facade must carry a real battle checkpoint end to end. The
 -- engine-side fixture is deliberately constructed outside the probe mod; the
 -- mod sees and calls only mod.checkpoints.
-local function makeBattleGame()
+local function makeBattleGame(kind)
   local data = Fixtures.fresh()
   local save = SaveData.newGame()
   save.meta.playthroughId = "public-battle-playthrough"
-  save.party = { Pokemon.new(data, "FIXMON_A", 20) }
+  save.party = { Pokemon.new(data, "FIXMON_A", 20),
+    Pokemon.new(data, "FIXMON_B", 19),
+    Pokemon.new(data, "FIXMON_C", 18) }
   -- The tiny fixture registry intentionally omits several full-game defaults.
   -- Normalize those once, then place the save on its fixture map.
   SaveData.validate(save, data)
@@ -387,7 +389,8 @@ local function makeBattleGame()
     self.player = { cellX = x, cellY = y, facing = facing, surfing = false }
   end
   function battleOw:restoreBattleContinuation(restoredBattle, origin)
-    if origin.kind ~= "wild_encounter" or origin.map ~= self.map.id then
+    local expected = kind == "trainer" and "trainer_encounter" or "wild_encounter"
+    if origin.kind ~= expected or origin.map ~= self.map.id then
       return false
     end
     restoredBattle.onFinish = function() end
@@ -397,9 +400,19 @@ local function makeBattleGame()
     data = data, save = save, stack = stack, overworld = battleOw,
   }, { __index = GameMethods })
   stack.states[1] = battleOw
-  local battle = BattleState.newWild(battleGame, "FIXMON_B", 12)
+  local battle
+  if kind == "trainer" then
+    battle = BattleState.newTrainer(battleGame, "OPP_FIX_YOUNGSTER", 1, {
+      playerPartyIndices = { 2, 3 },
+    })
+  else
+    battle = BattleState.newWild(battleGame, "FIXMON_B", 12)
+  end
   battle.phase, battle.queue = "menu", {}
-  battle.checkpointOrigin = { kind = "wild_encounter", map = "FIX_TOWN" }
+  battle.checkpointOrigin = kind == "trainer"
+    and { kind = "trainer_encounter", map = "FIX_TOWN", npcId = "TRAINER_1",
+      trainerClass = "OPP_FIX_YOUNGSTER", partyIndex = 1 }
+    or { kind = "wild_encounter", map = "FIX_TOWN" }
   battle.musicKind = battle:computeMusicKind()
   battle.onFinish = function() end
   stack.states[2] = battle
@@ -437,6 +450,62 @@ if battleSnapshot then
     "public battle capture/restore/capture is a normalized differential roundtrip")
 end
 
+checkpointRngState = "scoped-trainer-rng-A"
+local scopedGame, scopedBattle = makeBattleGame("trainer")
+local scopedSnapshot, scopedCaptureCode = checkpoints:capture(scopedGame)
+T.check(scopedSnapshot ~= nil,
+  "public checkpoints capture a scoped trainer battle: "
+    .. tostring(scopedCaptureCode))
+if scopedSnapshot then
+  T.same(scopedSnapshot.runtime.battle.playerPartyIndices, { 2, 3 },
+    "capture stores the battle-local save-party index scope")
+  local restored, code, message = checkpoints:restore(scopedGame, scopedSnapshot)
+  T.check(restored == true,
+    "public checkpoints restore a scoped trainer battle: "
+      .. tostring(code) .. " / " .. tostring(message))
+  local scopedRestored = scopedGame.stack:top()
+  T.same(scopedRestored.playerPartyIndices, { 2, 3 },
+    "restore reconstructs the same ordered party scope")
+  T.check(scopedRestored.playerParty[1] == scopedGame.save.party[2]
+      and scopedRestored.playerParty[2] == scopedGame.save.party[3],
+    "restored scope points at authoritative save-party records")
+
+  scopedSnapshot.runtime.battle.playerPartyIndices = nil
+  local oldRestored, oldCode = checkpoints:restore(scopedGame, scopedSnapshot)
+  T.check(oldRestored == true,
+    "an old checkpoint without party scope remains compatible: "
+      .. tostring(oldCode))
+  T.eq(scopedGame.stack:top().playerParty, nil,
+    "an old checkpoint restores the vanilla full-party view")
+end
+
+local function scopedCheckpoint()
+  local freshGame = makeBattleGame("trainer")
+  local snapshot = assert(checkpoints:capture(freshGame))
+  return freshGame, snapshot
+end
+
+local excludedGame, excludedSnapshot = scopedCheckpoint()
+excludedSnapshot.runtime.battle.player.index = 1
+local excludedRestored, excludedCode = checkpoints:restore(excludedGame,
+  excludedSnapshot)
+T.check(excludedRestored == false and excludedCode == "invalid_checkpoint",
+  "a scoped checkpoint rejects an active battler outside the eligible view")
+
+local malformedGame, malformedSnapshot = scopedCheckpoint()
+malformedSnapshot.runtime.battle.playerPartyIndices.extra = 3
+local malformedRestored, malformedCode = checkpoints:restore(malformedGame,
+  malformedSnapshot)
+T.check(malformedRestored == false and malformedCode == "invalid_checkpoint",
+  "a scoped checkpoint rejects non-array scope members instead of failing open")
+
+local participantGame, participantSnapshot = scopedCheckpoint()
+participantSnapshot.runtime.battle.participants = { 1 }
+local participantRestored, participantCode = checkpoints:restore(
+  participantGame, participantSnapshot)
+T.check(participantRestored == false and participantCode == "invalid_checkpoint",
+  "a scoped checkpoint rejects excluded participant references")
+
 -- The mod receives the normal public hook facade, never BattleState. START
 -- at the restored safe decision reaches its semantic auxiliary action without
 -- selecting a native command.

tests/modkit/cases/storage.lua

@@ -7,6 +7,7 @@ love = love or require("tests.love_stub")
 local T = require("tests.harness").suite("mod storage")
 local Loader = require("src.mods.Loader")
 local Runtime = require("src.mods.Runtime")
+local Storage = require("src.mods.Storage")
 local Version = require("src.core.Version")
 
 local savedEvents, savedHooks = Runtime.events, Runtime.hooks
@@ -22,7 +23,9 @@ local function memfs(files)
   function fs.read(path) return files[path] end
   function fs.write(path, body)
     if fs.failTmp and path:sub(-4) == ".tmp" then return false, "tmp denied" end
-    if fs.failMain and path:sub(-4) == ".lua" then return false, "main denied" end
+    if fs.failMain and (path:sub(-4) == ".lua" or path:sub(-4) == ".bin") then
+      return false, "main denied"
+    end
     files[path] = body
     return true
   end
@@ -107,6 +110,50 @@ T.same(loaded, payload, "stored payload roundtrips as data")
 T.check(loaded ~= payload and loaded.nested ~= payload.nested,
   "read returns decoded data rather than the caller's live table")
 
+T.check(type(alpha.writeBytes) == "function"
+    and type(alpha.readBytes) == "function",
+  "mod.storage exposes opaque byte read/write methods")
+if type(alpha.writeBytes) == "function" and type(alpha.readBytes) == "function" then
+  local binary = "MESH\0\1\255\128\nreturn _G.MOD_STORAGE_EXECUTED = true"
+  local binaryOk, binaryCode, binaryMessage =
+    alpha:writeBytes(current, "states/quick/blob", binary)
+  T.check(binaryOk == true,
+    "opaque bytes write exactly: " .. tostring(binaryCode or binaryMessage))
+  local binaryLoaded, binaryReadCode =
+    alpha:readBytes(current, "states/quick/blob")
+  T.eq(binaryLoaded, binary,
+    "opaque bytes round-trip without text or Lua decoding")
+  T.eq(binaryReadCode, nil, "successful opaque byte read has no error")
+  T.eq(_G.MOD_STORAGE_EXECUTED, nil,
+    "Lua-looking opaque bytes are never executed")
+
+  local emptyOk = alpha:writeBytes(current, "binary/empty", "")
+  T.check(emptyOk == true, "empty opaque byte payloads are valid")
+  T.eq(alpha:readBytes(current, "binary/empty"), "",
+    "empty opaque byte payloads round-trip")
+
+  local badBytes, badBytesCode =
+    alpha:writeBytes(current, "binary/bad-type", { byte = true })
+  T.check(not badBytes and badBytesCode == "invalid_bytes",
+    "non-string opaque payloads are rejected")
+
+  local savedLimit = Storage.MAX_BYTES
+  Storage.MAX_BYTES = 4
+  local tooLarge, tooLargeCode =
+    alpha:writeBytes(current, "binary/too-large", "12345")
+  Storage.MAX_BYTES = savedLimit
+  T.check(not tooLarge and tooLargeCode == "size_limit",
+    "opaque payloads over the per-key limit are rejected")
+
+  local tableConflict, tableConflictCode =
+    alpha:writeBytes(current, "states/quick/q1", "table-key-conflict")
+  T.check(not tableConflict and tableConflictCode == "type_conflict",
+    "bytes cannot replace a table record without deletion")
+  local wrongType, wrongTypeCode = alpha:read(current, "states/quick/blob")
+  T.check(wrongType == nil and wrongTypeCode == "type_mismatch",
+    "table reads identify byte records as the wrong storage type")
+end
+
 local bad, badCode = alpha:write(current, "states/bad", { callback = function() end })
 T.check(not bad and badCode == "encode_failed",
   "functions are rejected with a stable data-only error")
@@ -120,19 +167,33 @@ T.check(alpha:write(current, "states/quick/zeta", { n = 2 }), "write zeta")
 T.check(alpha:write(current, "states/quick/alpha", { n = 1 }), "write alpha")
 T.check(alpha:write(current, "settings", { enabled = true }), "write settings")
 local keys = alpha:list(current, "states/quick")
-T.same(keys, { "states/quick/alpha", "states/quick/q1", "states/quick/zeta" },
+T.same(keys, { "states/quick/alpha", "states/quick/blob",
+  "states/quick/q1", "states/quick/zeta" },
   "list returns sorted logical keys under the requested prefix")
 
 -- Mod, playthrough, and game namespaces cannot observe each other.
 local missing, missingCode = beta:read(current, "states/quick/q1")
 T.check(missing == nil and missingCode == "not_found",
   "another mod cannot read the first mod's payload")
+if type(alpha.readBytes) == "function" then
+  missing, missingCode = beta:readBytes(current, "states/quick/blob")
+  T.check(missing == nil and missingCode == "not_found",
+    "another mod cannot read the first mod's opaque payload")
+end
 missing, missingCode = alpha:read(game("red", "play-b"), "states/quick/q1")
 T.check(missing == nil and missingCode == "not_found",
   "another playthrough cannot read the payload")
 missing, missingCode = alpha:read(game("blue", "play-a"), "states/quick/q1")
 T.check(missing == nil and missingCode == "not_found",
   "another game version cannot read the payload")
+if type(alpha.readBytes) == "function" then
+  missing, missingCode = alpha:readBytes(game("red", "play-b"), "states/quick/blob")
+  T.check(missing == nil and missingCode == "not_found",
+    "another playthrough cannot read the opaque payload")
+  missing, missingCode = alpha:readBytes(game("blue", "play-a"), "states/quick/blob")
+  T.check(missing == nil and missingCode == "not_found",
+    "another game version cannot read the opaque payload")
+end
 
 -- Find the implementation-owned file only to inject corruption; assertions stay
 -- on public read behavior, not the path shape.
@@ -142,6 +203,12 @@ local function mainFor(fragment)
   end
 end
 
+local function byteMainFor(fragment)
+  for path in pairs(files) do
+    if path:find(fragment, 1, true) and path:sub(-4) == ".bin" then return path end
+  end
+end
+
 local q1Main = mainFor("q1")
 T.check(type(q1Main) == "string", "failure fixture locates the persisted q1")
 files[q1Main] = "not a serialized table"
@@ -158,6 +225,47 @@ T.check(not ok and code == "write_failed", "staging failure is reported")
 T.same(alpha:read(current, "replace"), { version = 1 },
   "staging failure leaves the prior value readable")
 
+if type(alpha.writeBytes) == "function" and type(alpha.readBytes) == "function" then
+  T.check(alpha:writeBytes(current, "binary/recover", "old-bytes"),
+    "seed opaque recovery value")
+  local recoverMain = byteMainFor("binary/recover")
+  T.check(type(recoverMain) == "string", "failure fixture locates opaque recovery data")
+  files[recoverMain] = nil
+  T.eq(alpha:readBytes(current, "binary/recover"), "old-bytes",
+    "missing opaque main recovers the last verified backup")
+
+  T.check(alpha:writeBytes(current, "binary/replace", "version-1"),
+    "seed opaque replacement value")
+  fs.failTmp = true
+  ok, code = alpha:writeBytes(current, "binary/replace", "version-2")
+  fs.failTmp = false
+  T.check(not ok and code == "write_failed",
+    "opaque staging failure is reported")
+  T.eq(alpha:readBytes(current, "binary/replace"), "version-1",
+    "opaque staging failure leaves the prior value readable")
+
+  fs.failMain = true
+  ok, code = alpha:writeBytes(current, "binary/replace", "version-3")
+  fs.failMain = false
+  T.check(not ok and code == "write_failed",
+    "opaque replacement failure is reported")
+  T.eq(alpha:readBytes(current, "binary/replace"), "version-1",
+    "opaque replacement failure leaves the prior value readable")
+
+  local byteConflict, byteConflictCode =
+    alpha:write(current, "binary/replace", { version = 3 })
+  T.check(not byteConflict and byteConflictCode == "type_conflict",
+    "tables cannot replace a byte record without deletion")
+
+  T.check(alpha:writeBytes(current, "binary/delete", "delete-me"),
+    "seed opaque delete target")
+  T.check(alpha:delete(current, "binary/delete") == true,
+    "delete removes an opaque record")
+  missing, missingCode = alpha:readBytes(current, "binary/delete")
+  T.check(missing == nil and missingCode == "not_found",
+    "deleted opaque key is unavailable")
+end
+
 -- Delete is exact and idempotent-not-found is explicit.
 T.check(alpha:write(current, "delete/me", { yes = true }), "seed delete target")
 T.check(alpha:write(current, "delete/keep", { yes = true }), "seed delete neighbor")

tests/modkit/cases/title_playthrough_context.lua

@@ -135,6 +135,17 @@ if type(storage) == "table" then
         "title binding supports safe same-namespace durable operations")
       T.same(selected:read("history/title-operation"), { allowed = true },
         "title durable operation remains scoped to the selected playthrough")
+      T.check(type(selected.writeBytes) == "function"
+          and type(selected.readBytes) == "function",
+        "selected storage exposes opaque byte methods")
+      if type(selected.writeBytes) == "function"
+          and type(selected.readBytes) == "function" then
+        local titleBytes = "TITLE\0\255-cache"
+        T.check(selected:writeBytes("history/title-bytes", titleBytes) == true,
+          "title binding writes opaque bytes in the selected namespace")
+        T.eq(selected:readBytes("history/title-bytes"), titleBytes,
+          "title binding reads opaque bytes in the selected namespace")
+      end
     end
     T.check(title.save.meta.playthroughId == nil,
       "opening title history never allocates or adopts a playthrough identity")

tests/modkit/cases/trainer_before_battle.lua

@@ -0,0 +1,92 @@
+-- A sandboxed mod can defer an ordinary trainer engagement and later resume
+-- it with a battle-local player-party scope, using only public mod surfaces.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+love = love or require("tests.love_stub")
+
+local T = require("tests.modkit")
+local OW = require("src.world.OverworldController")
+
+local FIXTURE = {
+  ["mods/scope_probe/manifest.json"] = [[{
+    "id": "scope_probe",
+    "name": "Scope Probe",
+    "version": "1.0.0",
+    "entry": "main.lua",
+    "api": 2
+  }]],
+  ["mods/scope_probe/main.lua"] = [[
+    local mod = ...
+    mod.hooks:wrap("trainer.before_battle", function(next, game, context, continue)
+      mod.exports.game = game
+      mod.exports.context = context
+      mod.exports.continue = continue
+      return true
+    end)
+  ]],
+}
+
+local vanilla = T.sdk.loadNone({})
+local vanillaCalls, vanillaOptions = 0
+OW.prepareTrainerBattle({ id = "game" }, {
+  trainerClass = "OPP_FIX_YOUNGSTER", partyIndex = 1,
+  mapId = "FIX_ROUTE", npcId = "TRAINER_1",
+}, function(options)
+  vanillaCalls, vanillaOptions = vanillaCalls + 1, options
+end)
+T.eq(vanillaCalls, 1, "no mod starts the trainer battle exactly once")
+T.eq(vanillaOptions, nil, "no mod supplies no battle-local party scope")
+vanilla.release()
+
+local run = T.sdk.loadMods({ "mods/scope_probe" }, {
+  fs = T.sdk.memfs(FIXTURE),
+})
+T.eq(#run.errors, 0,
+  "the public preparation probe loads clean (" .. tostring(run.errors[1]) .. ")")
+local game = { id = "live-game" }
+local calls, options = 0
+OW.prepareTrainerBattle(game, {
+  trainerClass = "OPP_FIX_YOUNGSTER", partyIndex = 2,
+  mapId = "FIX_ROUTE", npcId = "TRAINER_7",
+}, function(value)
+  calls, options = calls + 1, value
+end)
+T.eq(calls, 0, "a claiming public hook defers battle construction")
+local out = run.loader.exports.scope_probe or {}
+T.check(out.game == game, "the hook receives the live game")
+T.same(out.context, {
+  trainerClass = "OPP_FIX_YOUNGSTER", partyIndex = 2,
+  mapId = "FIX_ROUTE", npcId = "TRAINER_7",
+}, "the hook receives data-only trainer identity context")
+T.eq(out.continue({ playerPartyIndices = { 2, 4 } }), true,
+  "the retained continuation resumes the deferred battle")
+T.eq(calls, 1, "resume constructs the battle exactly once")
+T.same(options, { playerPartyIndices = { 2, 4 } },
+  "ordered eligible indices cross the public seam unchanged")
+T.eq(out.continue({ playerPartyIndices = { 1 } }), false,
+  "the continuation refuses a second invocation")
+T.eq(calls, 1, "a duplicate resume cannot start a second battle")
+run.release()
+
+local cancelRun = T.sdk.loadMods({ "mods/scope_probe" }, {
+  fs = T.sdk.memfs(FIXTURE),
+})
+local starts, cancels = 0, 0
+OW.prepareTrainerBattle(game, {
+  trainerClass = "OPP_FIX_YOUNGSTER", partyIndex = 2,
+  mapId = "FIX_ROUTE", npcId = "TRAINER_7",
+}, function()
+  starts = starts + 1
+end, function()
+  cancels = cancels + 1
+end)
+local cancelOut = cancelRun.loader.exports.scope_probe or {}
+T.eq(cancelOut.continue({ cancel = true }), true,
+  "the retained continuation can cancel a deferred encounter")
+T.eq(starts, 0, "cancelling never constructs a trainer battle")
+T.eq(cancels, 1, "cancelling invokes the encounter's completion callback")
+T.eq(cancelOut.continue(), false,
+  "a cancelled continuation remains one-shot")
+cancelRun.release()
+
+T.finish("trainer_before_battle")

tests/modkit/cases/world_field_items.lua

@@ -0,0 +1,88 @@
+-- Contextual bicycle and fishing actions share one public contract in both
+-- generations while each engine keeps ownership of its own field-item path.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.harness").suite("mod world field items")
+
+local facingWater = false
+local redWorld = {
+  isOverworld = true,
+  map = { id = "ROUTE_1", def = { tileset = "OVERWORLD" } },
+  player = { moving = false, inputLocked = false, surfing = false },
+  runner = { isRunning = function() return false end },
+  scriptMoves = {},
+  bikeAllowed = function() return true end,
+  facingIsShoreOrWater = function() return facingWater end,
+  useBicycle = function(self) self.bikeUsed = true return true end,
+  useFishingRod = function(self, rod) self.rodUsed = rod return true end,
+}
+local redGame = {
+  data = { items = { OLD_ROD = { name = "OLD ROD" } } },
+  save = { player = { name = "RED" }, party = {},
+    inventory = { BICYCLE = 1, OLD_ROD = 1 } },
+  stack = { states = { redWorld } },
+  overworld = redWorld,
+}
+function redGame.stack:top() return self.states[#self.states] end
+
+local RedAPI = require("src.world.WorldAPI")
+local red = RedAPI.new(redGame, "fixture")
+local RedWorld = require("src.world.OverworldController")
+T.check(type(RedWorld.useBicycle) == "function"
+    and type(RedWorld.useFishingRod) == "function",
+  "Red keeps field-item execution in its world")
+local actions = red:availableFieldActions()
+T.eq(actions[1].id, "bicycle", "Red lists an owned usable bicycle")
+T.check(red:useFieldAction("bicycle"), "Red accepts the listed bicycle")
+T.check(redWorld.bikeUsed, "Red delegates to its world-owned bicycle path")
+
+facingWater = true
+actions = red:availableFieldActions()
+T.eq(actions[2].rods[1].id, "OLD_ROD", "Red lists owned rods at water")
+T.check(red:useFieldAction("fish", { rod = "OLD_ROD" }),
+  "Red accepts a listed rod")
+T.eq(redWorld.rodUsed, "OLD_ROD", "Red delegates to its fishing path")
+local used = redWorld.rodUsed
+local ok, err = red:useFieldAction("fish", { rod = "SUPER_ROD" })
+T.check(not ok and err == "fishing rod unavailable",
+  "Red rejects an unowned rod")
+T.eq(redWorld.rodUsed, used, "a rejected Red rod changes nothing")
+
+redWorld.player.moving = true
+T.eq(#red:availableFieldActions(), 0, "Red hides actions while moving")
+ok, err = red:useFieldAction("bicycle")
+T.check(not ok and err == "world is busy",
+  "Red refuses a stale action while busy")
+
+local goldWorld = {
+  map = { id = "ROUTE_29", def = { environment = "ROUTE" } },
+  player = {}, playerState = "normal",
+  acceptsMenuInput = function() return true end,
+  playerCollision = function() return 0x00 end,
+  alwaysOnBike = function() return false end,
+  fieldContext = function() return { facingColl = 0x20 } end,
+  useFieldItem = function(self, item) self.itemUsed = item return "used" end,
+}
+local goldGame = {
+  data = { items = { OLD_ROD = { name = "OLD ROD" } } },
+  save = { inventory = { BICYCLE = 1, OLD_ROD = 1 } },
+  world = goldWorld,
+}
+
+local GoldAPI = require("src.world.gen2.WorldAPI")
+local gold = GoldAPI.new(goldGame, "fixture")
+actions = gold:availableFieldActions()
+T.eq(actions[1].id, "bicycle", "Gold shares the bicycle action id")
+T.eq(actions[2].rods[1].id, "OLD_ROD", "Gold shares the rod shape")
+T.check(gold:useFieldAction("fish", { rod = "OLD_ROD" }),
+  "Gold accepts the same fishing request")
+T.eq(goldWorld.itemUsed, "OLD_ROD",
+  "Gold delegates to its own field-item path")
+used = goldWorld.itemUsed
+ok, err = gold:useFieldAction("fish", { rod = "SUPER_ROD" })
+T.check(not ok and err == "fishing rod unavailable",
+  "Gold rejects an unowned rod")
+T.eq(goldWorld.itemUsed, used, "a rejected Gold rod changes nothing")
+
+T.finish()

tests/parity_escort_lockstep.lua

@@ -0,0 +1,88 @@
+-- Parity test: escort lockstep cadence.  An NPC walking the player to a
+-- destination moves under DoScriptedNPCMovement (engine/overworld/
+-- movement.asm:737), whose wScriptedNPCWalkCounter is 8 ticks of 2px --
+-- the player's own frames per cell, not MoveSprite's doubled NPC walk.
+-- Self-contained: run via `luajit tests/parity_escort_lockstep.lua`; also
+-- dofile'd by tests/run_tests.lua's aggregator.
+package.path = "./?.lua;./?/init.lua;" .. package.path
+if not _G.love then _G.love = require("tests.love_stub") end
+local Data = require("src.core.Data")
+if not (Data.maps and Data.maps.PALLET_TOWN) then Data:load() end
+local S = require("tests.harness").suite("parity escort lockstep")
+local check, eq = S.check, S.eq
+
+local SaveData = require("src.core.SaveData")
+local Game = require("src.core.Game")
+local StateStack = require("src.core.StateStack")
+local OverworldState = require("src.world.OverworldController")
+
+local prev = { data = Game.data, save = Game.save, stack = Game.stack,
+               input = Game.input, renderer = Game.renderer,
+               overworld = Game.overworld }
+Game.data = Data
+Game.save = SaveData.newGame(Data)
+Game.save.player.name = "RED"
+StateStack:init()
+Game.stack = StateStack
+Game.input = {
+  isDown = function() return false end,
+  wasPressed = function() return false end,
+  step = function() end, state = {}, pressQueue = {},
+}
+Game.renderer = {
+  beginWorldPass = function() end, endWorldPass = function() end,
+  beginUIPass = function() end, endUIPass = function() end,
+  worldViewSize = function() return 160, 144 end,
+  setSGBZones = function() end,
+}
+StateStack:push(OverworldState, "PALLET_TOWN", 10, 5, "down")
+local ow = OverworldState
+Game.overworld = ow
+
+-- A PALLET_TOWN object parked one cell ahead of the player, then walked
+-- in the paired-step pattern the escorts use: the NPC's step is queued
+-- without a callback and the player's carries the chain.
+local function runEscort(sync, steps)
+  local npc = ow.npcs[1]
+  local p = ow.player
+  p.cellX, p.cellY, p.px, p.py = 10, 5, 160, 80
+  p.moving, p.progress, p.targetX, p.targetY = false, 0, nil, nil
+  npc.cellX, npc.cellY, npc.px, npc.py = 10, 4, 160, 64
+  npc.moving, npc.progress, npc.targetX, npc.targetY = false, 0, nil, nil
+  ow.scriptMoves = {}
+  npc.stepFrames = sync and (p.stepFramesCur or p.stepFrames) or nil
+  local worstDrift, done, i = 0, false, 0
+  local function tick()
+    i = i + 1
+    if i > steps then done = true; return end
+    ow:scriptMove(npc, "down", 1)
+    ow:scriptMove(p, "down", 1, tick)
+  end
+  tick()
+  -- NPCs update before updateScriptMoves and the player after, so a
+  -- paired step leaves the NPC one frame (1px) behind for its whole cell
+  for _ = 1, 60 * steps do
+    ow:update(1)
+    local drift = math.abs((p.py - npc.py) - 16)
+    if drift > worstDrift then worstDrift = drift end
+    if done then break end
+  end
+  npc.stepFrames = nil
+  return { done = done, drift = worstDrift,
+           npcY = npc.cellY, playerY = p.cellY }
+end
+
+local synced = runEscort(true, 6)
+check(synced.done, "synced escort finishes")
+check(synced.drift <= 2,
+      ("synced NPC holds formation (worst drift %dpx)"):format(synced.drift))
+eq(synced.playerY - synced.npcY, 1, "synced NPC stays one cell ahead")
+
+-- The default NPC walk is MoveSprite's, half the player's rate: without
+-- the sync the escort desyncs, which is the bug this guards.
+local plain = runEscort(false, 6)
+check(plain.drift >= 16,
+      ("unsynced NPC lags a cell or more (worst drift %dpx)"):format(plain.drift))
+
+for k, v in pairs(prev) do Game[k] = v end
+S.finish()