prioritize interactive requests over background checks in shared Lichess-token queue

/today, /yesterday, /week were queuing behind the entire periodic-check
backlog on the same rate-limited LICHESS_APP_TOKEN (observed ~2min wait on
prod for a single command). Add a two-tier priority queue to SharedTokenGate:
interactive on-demand requests jump ahead of background periodic checks,
which still drain normally when nothing interactive is waiting. Verified
locally end-to-end (isolated queue unit tests, live request with priority
correctly reaching Lichess, and a real successful accuracy fetch rendered
through StatsFormatter).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

LichessClientTG_bot/bot.py

@@ -1119,7 +1119,8 @@ class LichessBot:
                         int(since_dt.timestamp() * 1000),
                         int(until_dt.timestamp() * 1000),
                         rated_only=True,
-                        include_games=want_rows
+                        include_games=want_rows,
+                        priority="interactive"
                     )
                 except Exception as e:
                     logger.warning(f"⚠️ Supplementary accuracy fetch failed for {username}/{period}: {e}")