perf(core): speed up packedTileUpdates (Uint32 pairs, no tile wrappers) (#3255)

## Description
Reduces CPU + GC pressure from tile update serialization.

**What changed**
- Switched `packedTileUpdates` from `BigUint64Array` (BigInt packing) to
`Uint32Array` `[tileRef, state]` pairs, updating `GameView` ingestion.
- Updated tile state to use `GameMap.tileState(tile)` and
`GameMap.updateTile(tile, state)`.
- Removed per-tile `GameUpdateType.Tile` wrapper allocations by
recording raw `(tile, state)` pairs in `GameImpl` and draining them via
`drainPackedTileUpdates()` in `GameRunner`.

**Why it’s faster**
- Avoids BigInt and pack/unpack.
- Avoids per-tile object allocations.

**Compatibility**
- Wire format change: `packedTileUpdates` is now `Uint32Array` pairs
instead of `BigUint64Array`.

## Please complete the following:

- [ ] I have added screenshots for all UI updates
- [ ] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [ ] I have added relevant tests to the test directory
- [ ] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

DISCORD_USERNAME

src/core/game/GameView.ts

@@ -25,7 +25,7 @@ import {
   UnitInfo,
   UnitType,
 } from "./Game";
-import { GameMap, TileRef, TileUpdate } from "./GameMap";
+import { GameMap, TileRef } from "./GameMap";
 import {
   AllianceView,
   AttackUpdate,
@@ -648,9 +648,13 @@ export class GameView implements GameMap {
     this.lastUpdate = gu;
 
     this.updatedTiles = [];
-    this.lastUpdate.packedTileUpdates.forEach((tu) => {
-      this.updatedTiles.push(this.updateTile(tu));
-    });
+    const packed = this.lastUpdate.packedTileUpdates;
+    for (let i = 0; i + 1 < packed.length; i += 2) {
+      const tile = packed[i];
+      const state = packed[i + 1];
+      this.updateTile(tile, state);
+      this.updatedTiles.push(tile);
+    }
 
     if (gu.updates === null) {
       throw new Error("lastUpdate.updates not initialized");
@@ -949,11 +953,11 @@ export class GameView implements GameMap {
   ): Set<TileRef> {
     return this._map.bfs(tile, filter);
   }
-  toTileUpdate(tile: TileRef): bigint {
-    return this._map.toTileUpdate(tile);
+  tileState(tile: TileRef): number {
+    return this._map.tileState(tile);
   }
-  updateTile(tu: TileUpdate): TileRef {
-    return this._map.updateTile(tu);
+  updateTile(tile: TileRef, state: number): void {
+    this._map.updateTile(tile, state);
   }
   numTilesWithFallout(): number {
     return this._map.numTilesWithFallout();