后端：游玩计数排序移出互斥锁

- game_play_counter.rs：drain 只负责在锁内取走增量，新增 sort_deltas 在释放锁后排序，避免 O(n log n) 排序阻塞并发 record

server-rs/crates/api-server/src/game_play_counter.rs

@@ -157,13 +157,17 @@ impl GamePlayCounter {
             return None;
         }
         state.last_flush_at = now;
-        Some(drain_pending(&mut state.pending))
+        let deltas = drain_pending(&mut state.pending);
+        drop(state);
+        Some(sort_deltas(deltas))
     }
 
     /// 无条件取走全部增量，供关停 flush 使用。
     pub fn take_pending(&self) -> Vec<GamePlayCountDelta> {
         let mut state = self.lock();
-        drain_pending(&mut state.pending)
+        let deltas = drain_pending(&mut state.pending);
+        drop(state);
+        sort_deltas(deltas)
     }
 
     /// 写库失败时把增量放回，等待下一次 flush。
@@ -207,11 +211,14 @@ impl GamePlayCounter {
 }
 
 fn drain_pending(pending: &mut HashMap<String, u64>) -> Vec<GamePlayCountDelta> {
-    let mut deltas = pending
+    pending
         .drain()
         .filter_map(|(game_id, delta)| (delta > 0).then_some(GamePlayCountDelta { game_id, delta }))
-        .collect::<Vec<_>>();
-    // 稳定批次顺序，便于测试与日志比对。
+        .collect()
+}
+
+/// 稳定批次顺序，便于测试与日志比对；调用方已释放计数锁，排序不阻塞并发 `record`。
+fn sort_deltas(mut deltas: Vec<GamePlayCountDelta>) -> Vec<GamePlayCountDelta> {
     deltas.sort_by(|left, right| left.game_id.cmp(&right.game_id));
     deltas
 }