Complete the overworld foundation

Port forced movement (turn delays, bumps, ice, currents, pits), dynamic
return warps, elevators, Surf, Cut, Strength and cycling rules, working
map blocks with changeblock/changemapblocks, and the remaining NPC
movement types and movement commands.

Add tileset animation from the ROM's command tables, grass sprite
priority and special map palettes; room decorations with ownership, the
bedroom PC and save migration; and Key Items access to the Bicycle.

Fourteen original-engine traces compare positions, facing, actors, event
flags and scripted poses. Tile animation matches original VRAM for four
tilesets, and LoadMapPals matches 192 palette cases. skyfall_top now
keeps the $60 sprite offset its step function leaves behind.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/check-reference.mjs

@@ -186,6 +186,8 @@ const ramNames = {
   hiddenItemID: "wHiddenItemID",
   runningTrainerBattleScript: "wRunningTrainerBattleScript",
   callerContact: "wCallerContact",
+  surfingPlayerState: "wSurfingPlayerState",
+  strengthSpecies: "wStrengthSpecies",
   moneyTemp: "hMoneyTemp",
 };
 const profile = readFileSync("src/game/rom/profile.ts", "utf8");
@@ -199,14 +201,14 @@ for (const [key, symbol] of Object.entries(ramNames)) {
   if (!match || Number(match[1]) !== ram.get(symbol))
     throw new Error(`Profile RAM mismatch: ${key} / ${symbol}`);
 }
-// BATTLE entries are keyed by their PRET labels.
-{
-  const block = /export const BATTLE = \{([\s\S]*?)\} as const;/.exec(profile)?.[1];
-  if (!block) throw new Error("Battle symbol table is missing.");
+// BATTLE and OVERWORLD entries are keyed by their PRET labels.
+for (const table of ["BATTLE", "OVERWORLD"]) {
+  const block = new RegExp(`export const ${table} = \\{([\\s\\S]*?)\\} as const;`).exec(profile)?.[1];
+  if (!block) throw new Error(`${table} symbol table is missing.`);
   for (const [, quoted, bare, literal] of block.matchAll(/^\s+(?:"([^"]+)"|(\w+)):\s*(0x[0-9a-f]+),/gm)) {
     const label = quoted ?? bare;
     if (symbols.get(label) !== Number(literal))
-      throw new Error(`Battle symbol mismatch: ${label}`);
+      throw new Error(`${table} symbol mismatch: ${label}`);
   }
 }
 if (!profile.includes(`NUM_TRAINER_CLASSES = ${(symbols.get("Trainers") - symbols.get("TrainerGroups")) / 2};`))
@@ -294,6 +296,9 @@ const pretConstants = new Map();
         pretConstants.set(match[2], stored);
         if (match[1] === "shift_const") pretConstants.set(`${match[2]}_F`, value);
         value += step;
+      } else if ((match = /^DEF\s+(\w+)\s+EQU\s+const_value\s*-\s*(\w+)$/.exec(line))) {
+        const offset = /^\d+$/.test(match[2]) ? Number(match[2]) : pretConstants.get(match[2]);
+        if (offset !== undefined) pretConstants.set(match[1], value - offset);
       } else if ((match = /^DEF\s+(\w+)\s+EQU\s+([$%]?[0-9a-fA-F]+|\w+)$/.exec(line))) {
         const target = match[2];
         const resolved =
@@ -307,7 +312,9 @@ const pretConstants = new Map();
     }
   }
 }
-const battleConstants = readFileSync("src/game/battle/constants.ts", "utf8");
+const battleConstants = ["src/game/battle/constants.ts", "src/game/world/constants.ts"]
+  .map((file) => readFileSync(file, "utf8"))
+  .join("\n");
 for (const [, block] of battleConstants.matchAll(/export const \w+ = \{([\s\S]*?)\} as const;/g)) {
   for (const [, name, literal] of block.matchAll(/^\s+(\w+):\s*(0x[0-9a-f]+|\d+),/gim)) {
     const expected = pretConstants.get(name);