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/movement-fixture.ts

@@ -0,0 +1,90 @@
+import { emptyDecorations } from "../src/game/world/decorations";
+import { CrystalAssets } from "../src/game/rom/assets";
+import { GameWorld } from "../src/game/world/world";
+import type { GameMap } from "../src/game/world/types";
+
+/** Synthetic maps and script bytes: these tests run without a private ROM. */
+export class MovementAssets extends CrystalAssets {
+  readonly fixtures = new Map<string, GameMap>();
+  readonly tiles = new Map<string, number>();
+  readonly bytes: Uint8Array;
+  constructor() {
+    const bytes = new Uint8Array(0xa0000);
+    bytes[0] = 0x50; // Empty weekday name for synthetic script hosts.
+    super(bytes);
+    this.bytes = bytes;
+    for (const id of ["24:7", "24:6"]) {
+      this.fixtures.set(id, {
+        id,
+        group: 24,
+        number: Number(id.split(":")[1]),
+        name: id,
+        location: id,
+        landmark: 1,
+        width: 8,
+        height: 8,
+        border: 0,
+        tileset: 1,
+        environment: 1,
+        paletteMode: 1,
+        blocks: new Uint8Array(16),
+        warps: [],
+        backgroundEvents: [],
+        objects: [],
+        connections: [],
+        sceneScripts: [],
+        callbacks: [],
+        coordinateEvents: [],
+      });
+    }
+  }
+  override map(id: string) {
+    return this.fixtures.get(id)!;
+  }
+  override isPorted(id: string) {
+    return this.fixtures.has(id);
+  }
+  override sceneOwner() {
+    return undefined;
+  }
+  override collision(map: GameMap, x: number, y: number) {
+    if (x < 0 || y < 0 || x >= map.width || y >= map.height) return 7;
+    return this.tiles.get(`${map.id}:${x},${y}`) ?? 0;
+  }
+  /** CollisionPermissionTable in brief: walls, then the water rows
+   * ($2x, $3x, buoys $cx) apart from ice and the wall-like buoy tiles. */
+  override permission(collision: number) {
+    if (collision === 7 || collision === 0x27 || collision === 0x2f) return 15;
+    if (collision === 0x23 || collision === 0x2b) return 0;
+    return [0x20, 0x30, 0xc0].includes(collision & 0xf0) ? 1 : 0;
+  }
+  override grassCollisions() {
+    return [];
+  }
+  override sprite(id: number) {
+    return id ? { graphics: new Uint8Array(0), palette: 0, walking: false } : undefined;
+  }
+  tile(x: number, y: number, collision: number, map = "24:7") {
+    this.tiles.set(`${map}:${x},${y}`, collision);
+  }
+}
+
+export function fixture() {
+  const assets = new MovementAssets();
+  const world = new GameWorld(
+    assets,
+    () => new Date("2026-09-22T12:00:00"),
+    () => 0,
+  );
+  world.state.decorations = emptyDecorations();
+  return { assets, world };
+}
+
+export function connectWarp(assets: MovementAssets, x = 3, y = 4) {
+  assets.map("24:7").warps.push({ x, y, targetMap: "24:6", targetWarp: 1 });
+  assets
+    .map("24:6")
+    .warps.push({ x: 2, y: 2, targetMap: "24:7", targetWarp: 1 });
+  assets.tile(2, 2, 0x70, "24:6");
+}
+