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/overworld-routines.spec.ts

@@ -0,0 +1,101 @@
+import { test, expect } from "@playwright/test";
+import { existsSync, readFileSync } from "node:fs";
+import { CrystalAssets } from "../src/game/rom/assets";
+
+const romPath =
+  process.env.CRYSTAL_ROM_PATH ??
+  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
+const symbolsPath = ".reference/pokecrystal/pokecrystal11.sym";
+test("all tileset palettes match the original LoadMapPals routine", async ({
+  page,
+}, info) => {
+  test.skip(
+    info.project.name !== "chromium" ||
+      !existsSync(romPath) ||
+      !existsSync(symbolsPath),
+    "Requires the local ROM/reference; engine comparison runs in Chromium.",
+  );
+  const symbols: Record<string, { bank: number; address: number }> = {};
+  for (const line of readFileSync(symbolsPath, "utf8").split("\n")) {
+    const m = /^([0-9a-f]{2}):([0-9a-f]{4}) (\S+)$/.exec(line);
+    if (m)
+      symbols[m[3]] = { bank: parseInt(m[1], 16), address: parseInt(m[2], 16) };
+  }
+  const bytes = new Uint8Array(readFileSync(romPath));
+  const cases = Array.from({ length: 36 * 4 }, (_, i) => ({
+    tileset: 1 + Math.floor(i / 4),
+    time: i % 4,
+    environment: 3,
+    group: 24,
+  }));
+  for (const environment of [1, 2, 4, 7])
+    for (const time of [0, 1, 2, 3])
+      for (const tileset of [1, 29, 30])
+        cases.push({ tileset, time, environment, group: 24 });
+  await page.goto("/reference.html");
+  const original = await page.evaluate(
+    async ({ rom, symbols, cases }) => {
+      const { BinjgbEmulator } = await import("/src/emulator/binjgb.ts");
+      const emu = new BinjgbEmulator();
+      await emu.load(new Uint8Array(rom), document.createElement("canvas"));
+      const write = (name: string, value: number) =>
+        emu.writeMemory(symbols[name].address, value);
+      const target = symbols.LoadMapPals;
+      const program = [
+        0xf3,
+        0x31,
+        0xfe,
+        0xc7,
+        0x3e,
+        target.bank,
+        0xe0,
+        0x9d,
+        0xea,
+        0,
+        0x20,
+        0xcd,
+        target.address & 255,
+        target.address >> 8,
+        0x3e,
+        0x42,
+        0xea,
+        0xff,
+        0xc6,
+        0x18,
+        0xfe,
+      ];
+      const output = cases.map((c) => {
+        emu.writeMemory(0xff70, 1);
+        write("wMapTileset", c.tileset);
+        write("wEnvironment", c.environment);
+        write("wTimeOfDayPal", c.time);
+        write("wMapGroup", c.group);
+        emu.writeMemory(0xc6ff, 0);
+        program.forEach((v, i) => emu.writeMemory(0xc000 + i, v));
+        emu.setProgramCounter(0xc000);
+        emu.advanceFrames(2);
+        if (emu.readMemory(0xc6ff) !== 0x42)
+          throw new Error("LoadMapPals did not return");
+        emu.writeMemory(0xff70, symbols.wBGPals1.bank);
+        return Array.from({ length: 32 }, (_, i) => {
+          const p = symbols.wBGPals1.address + i * 2;
+          const value = emu.readMemory(p) | (emu.readMemory(p + 1) << 8);
+          return [0, 5, 10].map((shift) =>
+            Math.round((((value >> shift) & 31) * 255) / 31),
+          );
+        });
+      });
+      emu.dispose();
+      return output;
+    },
+    { rom: [...bytes], symbols, cases },
+  );
+  const assets = new CrystalAssets(bytes),
+    base = assets.map("24:6");
+  cases.forEach((c, i) =>
+    expect(
+      assets.palettes({ ...base, ...c }, c.time).flat(),
+      JSON.stringify(c),
+    ).toEqual(original[i]),
+  );
+});