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>

src/emulator/binjgb.ts

@@ -262,6 +262,24 @@ export class BinjgbEmulator implements Emulator {
     this.canvas!.putImageData(this.frame!, 0, 0);
   }
 
+  /** Development-only: run a bounded number of CPU cycles, to align frame
+   * sampling with a scanline when comparing against native routines. */
+  advanceCycles(cycles: number) {
+    if (
+      !this.handle ||
+      this.raf ||
+      !Number.isInteger(cycles) ||
+      cycles < 1 ||
+      cycles > 70224
+    )
+      throw new Error("Pause the reference before bounded cycle stepping.");
+    const module = this.module!;
+    const target = module._emulator_get_ticks_f64(this.handle) + cycles;
+    for (let events = 0; events < 100; events++)
+      if (module._emulator_run_until_f64(this.handle, target) & 4) return;
+    throw new Error("Reference cycle budget exceeded.");
+  }
+
   private fileData(
     kind: "state" | "ext_ram",
     action: (pointer: number, bytes: Uint8Array) => void,