Per-category GAME SPEED: overworld/battle/menu + core.logic_speed hook (RFC 0007)

GameSpeed is a single fast-forward multiplier applied uniformly to the
whole logic clock -- overworld walking, menu navigation and battle turns
all scale together. A player who wants 4X battles but 1X overworld (so a
cutscene or NPC dialogue doesn't blur past) has no way to get both.

Splits save.options.speed into speedOverworld/speedBattle/speedMenu, each
cycling independently, with an automatic migration so an existing save's
speed choice carries over. Game.speedCategoryInStack resolves which
category is active by walking the state stack (the same idiom
wideBattleInStack/fillScaleInStack already use), so a menu opened mid-
battle inherits battle speed rather than resetting to whatever "menu"
defaults to. Adds a new core.logic_speed hook so a mod can read or
override the resolved multiplier for the current frame regardless of
which category produced it, sitting after the link-play and run-argument
overrides so neither is a seam a mod can defeat.

RFC 0007 status: Proposed.

src/import/LauncherSettings.lua

@@ -214,10 +214,24 @@ local function coreRows(opts, hooks)
 
   local okSpd, GameSpeed = pcall(require, "src.core.GameSpeed")
   if okSpd then
-    add(Strings("GAME SPEED"),
-      function() return GameSpeed.levelLabel(opts.speed) end,
+    -- Per-category (RFC 0007): overworld/battle/menu each cycle their own
+    -- multiplier, mirroring OptionsMenu.lua's three rows.
+    add(Strings("OVERWORLD SPEED"),
+      function() return GameSpeed.levelLabel(opts.speedOverworld) end,
       function(dir)
-        opts.speed = GameSpeed.cycle(opts.speed, dir)
+        opts.speedOverworld = GameSpeed.cycle(opts.speedOverworld, dir)
+        return true
+      end)
+    add(Strings("BATTLE SPEED"),
+      function() return GameSpeed.levelLabel(opts.speedBattle) end,
+      function(dir)
+        opts.speedBattle = GameSpeed.cycle(opts.speedBattle, dir)
+        return true
+      end)
+    add(Strings("MENU SPEED"),
+      function() return GameSpeed.levelLabel(opts.speedMenu) end,
+      function(dir)
+        opts.speedMenu = GameSpeed.cycle(opts.speedMenu, dir)
         return true
       end)
   end