Export versioned mod option schemas

src/mods/Loader.lua

@@ -19,6 +19,8 @@ local Loader = {}
 Loader.__index = Loader
 
 local MOD_STATE_FILE = "mod_state.lua" -- legacy migration only
+local OPTION_SCHEMAS_FILENAME = "mod_option_schemas.json"
+local OPTION_SCHEMAS_VERSION = 1
 
 -- walk a dotted target path without creating anything; the base view a
 -- registry folds against must never perturb Data on a mod-free boot
@@ -191,6 +193,43 @@ function Loader:_saveState()
   SaveData.saveOptions(options, self.fs)
 end
 
+-- Export the runtime option schemas after mod entry chunks have run.  This
+-- is an optional, data-only handoff for native launchers: they must not run
+-- arbitrary mod code before boot just to discover settings.  The snapshot is
+-- deliberately written beside options.lua so every platform's native shell
+-- can use the same filesystem contract.
+function Loader:_writeOptionSchemas()
+  if not self.fs.write then return end
+
+  local mods = {}
+  for id, schema in pairs(self.optionSchemas) do
+    if self.mods[id] and self.mods[id].enabled and not self.mods[id].failed then
+      mods[id] = schema
+    end
+  end
+
+  -- Do not create storage on a fresh mod-free boot, but do overwrite an old
+  -- snapshot when the current boot has no schemas so disabled/failed mods do
+  -- not leave stale native settings rows behind.
+  if next(mods) == nil
+      and not (self.fs.getInfo and self.fs.getInfo(OPTION_SCHEMAS_FILENAME)) then
+    return
+  end
+
+  local ok, encoded = pcall(Json.encode, {
+    schema_version = OPTION_SCHEMAS_VERSION,
+    mods = mods,
+  })
+  if not ok then
+    Logger.warn("mod option schema export: failed to encode: %s", tostring(encoded))
+    return
+  end
+  local written, err = self.fs.write(OPTION_SCHEMAS_FILENAME, encoded)
+  if not written then
+    Logger.warn("mod option schema export: failed to write: %s", tostring(err))
+  end
+end
+
 function Loader:setEnabled(id, enabled)
   if not self.mods[id] then return false end
   self.disabled[id] = not enabled
@@ -1089,6 +1128,7 @@ function Loader:load(data)
   -- which resolves every path to itself (14 §asset resolution).
   Assets.installLoader(self)
   self.events:emit("mods.loaded", { loader = self, data = data })
+  self:_writeOptionSchemas()
   self.initialized = true
   return #self.errors == 0
 end