fix(server): mark games abandoned on room teardown + staging leaderboard

When handle_player_leave emptied a room or handle_end_game was invoked,
the room was removed from memory without touching games_v2. Periodic
cleanup only scans in-memory rooms, so those rows were stranded as
status='active' forever — staging had 42 orphans accumulated over 5h.

- event_store.update_game_abandoned: guarded UPDATE (status='active' only)
- GameLogger.log_game_abandoned{,_async}: fire-and-forget wrapper
- handle_end_game + handle_player_leave: flip status before remove_room
- LEADERBOARD_INCLUDE_TEST_DEFAULT: env override so staging can show
  soak-harness accounts by default; prod keeps them hidden

Verified on staging: 42 orphans swept on restart, soak accounts now
visible on /api/stats/leaderboard (rank 1-4).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/services/game_logger.py

@@ -164,6 +164,24 @@ class GameLogger:
             # Not in async context - skip (simulations don't need this)
             pass
 
+    async def log_game_abandoned_async(self, game_id: str) -> None:
+        """Mark game as abandoned (room emptied before GAME_OVER)."""
+        try:
+            await self.event_store.update_game_abandoned(game_id)
+            log.debug(f"Logged game abandoned: {game_id}")
+        except Exception as e:
+            log.error(f"Failed to log game abandoned: {e}")
+
+    def log_game_abandoned(self, game_id: str) -> None:
+        """Sync wrapper: fires async task in async context, no-op otherwise."""
+        if not game_id:
+            return
+        try:
+            asyncio.get_running_loop()
+            asyncio.create_task(self.log_game_abandoned_async(game_id))
+        except RuntimeError:
+            pass
+
     # -------------------------------------------------------------------------
     # Move Logging
     # -------------------------------------------------------------------------