Fix QueuePool exhaustion: close leaked connections + widen pool + fix 2026 retry loop

- _fire_completion: add finally block to always close fresh_conn, preventing
daemon threads from leaking connections that exhaust the pool
- remote_db: raise pool_size 5→10, max_overflow 10→20, pool_timeout 30→60
to tolerate burst connections during live game windows
- render_statcast_retry_fragment: exclude games in live_pitch_mix_2026 from
pending query so 2026 games no longer perpetually re-trigger _fire_completion

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

app.py

@@ -403,12 +403,19 @@ def _fire_completion(pk_str: str, game_date: str, scores_df: pd.DataFrame) -> No
     scores_snapshot = scores_df.copy()
 
     def _run() -> None:
+        fresh_conn = None
         try:
             from database.db import get_connection as _get_conn
             fresh_conn = _get_conn()
             on_game_complete(fresh_conn, int(pk_str), game_date, scores_snapshot)
         except Exception as exc:
             logger.warning("[_fire_completion] thread error game_pk=%s: %s", pk_str, exc)
+        finally:
+            if fresh_conn is not None:
+                try:
+                    fresh_conn.close()
+                except Exception:
+                    pass
 
     t = threading.Thread(target=_run, daemon=True)
     t.start()
@@ -475,6 +482,10 @@ def render_statcast_retry_fragment() -> None:
                       SELECT 1 FROM statcast_event_core s
                       WHERE s.game_pk = g.game_pk::BIGINT
                   )
+                  AND NOT EXISTS (
+                      SELECT 1 FROM live_pitch_mix_2026 lpm
+                      WHERE lpm.game_pk = g.game_pk::BIGINT
+                  )
                 ORDER BY g.graded_at DESC
                 LIMIT 10
             """),

database/remote_db.py

@@ -29,6 +29,9 @@ def _get_engine():
 
     _engine = create_engine(
         database_url,
+        pool_size=10,
+        max_overflow=20,
+        pool_timeout=60,
         pool_pre_ping=True,
         pool_recycle=300,
     )