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>

tests/decorations.test.ts

@@ -0,0 +1,166 @@
+import { describe, expect, it } from "vitest";
+import { existsSync, readFileSync } from "node:fs";
+import { CrystalAssets } from "../src/game/rom/assets";
+import { GameWorld } from "../src/game/world/world";
+import {
+  DecorationData,
+  initialDecorations,
+} from "../src/game/world/decorations";
+import { EVENTS } from "../src/game/rom/profile";
+import { settle } from "./world-driver";
+
+const romPath =
+  process.env.CRYSTAL_ROM_PATH ??
+  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
+function fixture() {
+  const assets = new CrystalAssets(new Uint8Array(readFileSync(romPath)));
+  const world = new GameWorld(
+    assets,
+    () => new Date("2026-09-22T12:00:00"),
+    () => 0,
+  );
+  return {
+    assets,
+    world,
+    data: new DecorationData(assets.reader, assets.pokemon),
+  };
+}
+function pc(world: GameWorld) {
+  const save = world.save();
+  world.restore({
+    ...save,
+    map: "24:7",
+    x: 2,
+    y: 2,
+    direction: "up",
+    objects: [],
+  });
+  world.interact();
+  expect(world.notice, world.diagnostic).toBe("");
+  expect(world.dialogue?.choice?.kind).toBe("menu");
+}
+function choose(world: GameWorld, name: string) {
+  const choice = world.dialogue?.choice;
+  if (choice?.kind !== "menu") throw new Error("Expected decoration menu");
+  const index = choice.items.indexOf(name);
+  expect(index, name).toBeGreaterThanOrEqual(0);
+  world.choose(index);
+}
+function acknowledge(world: GameWorld) {
+  for (let i = 0; world.dialogue && !world.dialogue.choice && i < 20; i++)
+    world.advanceDialogue();
+}
+
+describe.skipIf(!existsSync(romPath))("room decorations", () => {
+  it("starts with the original bed and Town Map and migrates old saves", () => {
+    const { world, assets } = fixture();
+    expect(world.state.decorations).toEqual(initialDecorations());
+    expect(assets.block(world.map, 0, 4)).toBe(0x1b);
+    expect(assets.block(world.map, 6, 0)).toBe(0x1f);
+    expect(world.state.events.has(EVENTS.playersRoomPoster)).toBe(true);
+    const old = world.save() as Partial<ReturnType<GameWorld["save"]>>;
+    delete old.decorations;
+    world.restore(old);
+    expect(world.state.decorations).toEqual(initialDecorations());
+  });
+
+  it("PC puts away and restores a bed; mid-menu saves retain committed choices", () => {
+    const { world, assets } = fixture();
+    pc(world);
+    choose(world, "BED");
+    choose(world, "PUT IT AWAY");
+    expect(world.liveState.decorations.bed).toBe(0);
+    expect(world.save().decorations.bed).toBe(2);
+    acknowledge(world);
+    choose(world, "EXIT");
+    settle(world);
+    expect(world.state.decorations.bed).toBe(0);
+    expect(assets.block(world.map, 0, 4)).toBe(
+      assets.block(assets.map("24:7"), 0, 4),
+    );
+    world.restore(world.save());
+    pc(world);
+    choose(world, "BED");
+    choose(world, "FEATHERY BED");
+    acknowledge(world);
+    choose(world, "EXIT");
+    settle(world);
+    expect(assets.block(world.map, 0, 4)).toBe(0x1b);
+  });
+
+  it("owned ornaments move between sides without duplication and reload as sprites", () => {
+    const { world, data } = fixture();
+    world.state.events.add(data.attribute(30).event);
+    pc(world);
+    choose(world, "ORNAMENT");
+    choose(world, "PIKACHU DOLL");
+    choose(world, "RIGHT SIDE");
+    acknowledge(world);
+    choose(world, "ORNAMENT");
+    choose(world, "PIKACHU DOLL");
+    choose(world, "LEFT SIDE");
+    acknowledge(world);
+    choose(world, "EXIT");
+    settle(world);
+    expect([
+      world.state.decorations.left,
+      world.state.decorations.right,
+    ]).toEqual([30, 0]);
+    expect(world.objects().some((object) => object.id === 3)).toBe(true);
+    expect(world.objects().some((object) => object.id === 4)).toBe(false);
+    world.restore(world.save());
+    expect(world.state.variables[1]).toBe(data.attribute(30).sprite);
+  });
+
+  it("validates ownership and categories before changing the current game", () => {
+    const { world } = fixture();
+    const before = world.save();
+    for (const decorations of [
+      null,
+      { ...before.decorations, bed: 30 },
+      { ...before.decorations, bed: 3 },
+      { ...before.decorations, poster: 999 },
+    ]) {
+      expect(() => world.restore({ ...before, decorations })).toThrow(
+        /Invalid native save/,
+      );
+      expect(world.save()).toEqual(before);
+    }
+  });
+
+  it("sets every tile category and sprite category from the owned ROM attributes", () => {
+    const { world, assets, data } = fixture();
+    for (let id = 1; id <= 52; id++) {
+      const a = data.attribute(id);
+      if (a.action & 1) world.state.events.add(a.event);
+    }
+    world.state.decorations = {
+      bed: 5,
+      carpet: 10,
+      plant: 14,
+      poster: 19,
+      console: 24,
+      bigDoll: 28,
+      left: 51,
+      right: 52,
+    };
+    world.warpTo("24:7", 2, 2);
+    expect(
+      [
+        [0, 4],
+        [7, 4],
+        [6, 0],
+        [0, 0],
+        [0, 2],
+        [2, 2],
+        [4, 2],
+      ].map(([x, y]) => assets.block(world.map, x, y)),
+    ).toEqual([0x1e, 0x22, 0x25, 0x11, 0x12, 0x13, 0x12]);
+    expect([0, 1, 2, 3].map((i) => world.state.variables[i])).toEqual(
+      [24, 51, 52, 28].map((id) => data.attribute(id).sprite),
+    );
+    expect(world.objects()).toHaveLength(4);
+    world.restore(world.save());
+    expect(world.objects()).toHaveLength(4);
+  });
+});