fix(bot): harden ws.ts integration seam

- maybeAbandon Promise no longer floats from setTimeout
- broadcastSinceLast loses dead extra parameter
- bot-slot token is randomized so a third party can't hijack the
  bot's color by guessing a fixed placeholder

packages/server/src/games.ts

@@ -93,10 +93,11 @@ function makeSlot(token: PlayerToken, now: number) {
 }
 
 function makeBotSlot(now: number) {
-  // Synthetic slot: occupies the player's color but never connects.
-  // Token is a 24-char placeholder; never matches a real client.
+  // Synthetic slot: occupies the player's color but never connects. The token
+  // is randomized (same shape as a real client token) so a third party can't
+  // hijack the bot's color by guessing a fixed placeholder.
   return {
-    token: 'bot' + 'x'.repeat(21),
+    token: newPlayerToken(),
     socket: null,
     joinedAt: now,
     rateBucket: { tokens: RATE_LIMIT.capacity, last: now },

packages/server/src/ws.ts

@@ -32,20 +32,12 @@ async function pokeBot(game: Game): Promise<void> {
   }
 }
 
-function broadcastSinceLast(
-  game: Game,
-  extra?: { touchedPieceFor?: Color; touchedPiece?: import('@blind-chess/shared').Square },
-): void {
+function broadcastSinceLast(game: Game): void {
   for (const c of ['w', 'b'] as const) {
     const lastIdx = game.lastBroadcastIdx[c];
     const all = game.announcements;
     const slice = all.slice(lastIdx).filter((a) => a.audience === 'both' || a.audience === c);
-    sendUpdateTo(
-      game,
-      c,
-      slice,
-      extra?.touchedPieceFor === c ? { touchedPiece: extra.touchedPiece } : undefined,
-    );
+    sendUpdateTo(game, c, slice);
     game.lastBroadcastIdx[c] = all.length;
   }
 }
@@ -249,7 +241,7 @@ function onClose(ctx: SocketCtx): void {
     if (game.status === 'active') {
       game.disconnectAt[color] = Date.now();
       // Schedule grace timer.
-      setTimeout(() => maybeAbandon(game, color), GRACE_MS + 100);
+      setTimeout(() => { void maybeAbandon(game, color); }, GRACE_MS + 100);
     }
     notifyPeer(game, color, false, Date.now() + GRACE_MS);
   }