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/battle-browser.spec.ts

@@ -25,8 +25,10 @@ async function start(page: Page, scenario: BattleScenario = "win") {
   await page.locator("#play").click();
   for (const direction of ENCOUNTER_WALK) {
     const key = `Arrow${direction[0].toUpperCase()}${direction.slice(1)}`;
+    // Long enough to turn in place first (4 ticks) and start one step,
+    // short of a second step when already facing that way.
     await page.keyboard.down(key);
-    await page.clock.runFor(70);
+    await page.clock.runFor(250);
     await page.keyboard.up(key);
     await page.clock.runFor(300);
   }