replace getPlayerLookup with getAllPlayerIds in room manager

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/server/src/rooms/room-manager.ts

@@ -148,14 +148,10 @@ export class RoomManager {
 		return room?.gameManager ?? null
 	}
 
-	getPlayerLookup(code: string): Map<string, string> {
+	getAllPlayerIds(code: string): string[] {
 		const room = this.rooms.get(code)
-		if (!room) return new Map()
-		const lookup = new Map<string, string>()
-		for (const player of room.players.values()) {
-			lookup.set(player.id, player.displayName)
-		}
-		return lookup
+		if (!room) return []
+		return Array.from(room.players.values()).map((p) => p.id)
 	}
 
 	getPlayerIdBySession(code: string, sessionId: string): string | null {