fix: reduce chess-results.com request volume by ~20-50x

- check_all_subscriptions: quick pre-check (1 req, art=4 only) before
  full fetch; full fetch only when results_count or current_round changed.
  Interval 60s → 300s. Saves ~10,000 req/day per active subscription.
- rescan_existing_tournaments: filter to tournaments ended within last 30
  days (or no end_date). Drops from ~2000 cached TNRs to ~30-100 active
  ones per run, saving ~22,000 req/day.
- warmup: sleep 1s per TNR instead of 20ms per 500 — spreads initial
  full-scan over hours rather than minutes.
- parser: extract _normalize_url helper, add fetch_tournament_quick().

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

bots/tracker.py

@@ -768,21 +768,31 @@ def _warmup_cache_sync():
         if tnr % 100 == 0:
             set_tnr_state('warmup_tnr', str(tnr))
         if tnr % 500 == 0:
-            elapsed = (start_tnr - tnr) // 500 * 500  # rough
             print(f'warmup: progress TNR {tnr} (started at {start_tnr})', file=sys.stderr)
-            time.sleep(0.02)
+        # Rate-limit: ~1 req/sec to stay within chess-results.com daily limit.
+        # Cached TNRs return instantly (no HTTP), so this only applies to misses.
+        time.sleep(1.0)
 
     # Mark warmup as complete — next run will see this and skip
     set_tnr_state('warmup_tnr', 'done')
 
 
 async def rescan_existing_tournaments(context):
-    """Every 2h: refetch art=0 for all cached TNRs, detect new players."""
+    """Every 2h: refetch art=0 for recent/active cached TNRs, detect new players.
+
+    Only rescans tournaments that ended within the last 30 days (or have no
+    end_date). Old completed tournaments never get new players, so skipping
+    them keeps daily request volume within chess-results.com rate limits.
+    """
     import time
+    from datetime import timedelta
     from bots.client_bot import _md_escape as _md_esc
 
+    cutoff = (date.today() - timedelta(days=30)).isoformat()
     conn = _get_conn()
-    cached_tnrs = [r[0] for r in conn.execute('SELECT tnr FROM tnr_cache ORDER BY tnr DESC').fetchall()]
+    cached_tnrs = [r[0] for r in conn.execute(
+        'SELECT tnr FROM tnr_cache WHERE end_date = "" OR end_date >= ? ORDER BY tnr DESC',
+        (cutoff,)).fetchall()]
     conn.close()
     if not cached_tnrs:
         return
@@ -840,7 +850,7 @@ async def rescan_existing_tournaments(context):
 
 
 async def check_all_subscriptions(context):
-    from swiss_calc.parser import fetch_tournament
+    from swiss_calc.parser import fetch_tournament, fetch_tournament_quick
     from swiss_calc.swiss import calculate_next_round
     from bots.client_bot import format_pairings, _render_chunks
     from telegram.constants import ParseMode
@@ -849,10 +859,22 @@ async def check_all_subscriptions(context):
     if not subs:
         return
 
-    today_str = date.today().isoformat()
     for sub in subs:
         if sub['tournament_url'] == 'fide_only':
             continue
+
+        # Quick check: 1 request — skip full fetch if nothing changed
+        try:
+            quick = fetch_tournament_quick(sub['tournament_url'])
+        except Exception:
+            continue
+        quick_player = find_player(quick, sub['player_name'], sub['player_sno'])
+        quick_results = len(quick_player.get('results', [])) if quick_player else 0
+        quick_rd = quick.get('current_round', 0)
+        if quick_results <= sub['last_results_count'] and quick_rd <= sub['last_round_done']:
+            continue
+
+        # Something changed — do full fetch for accurate data and pairing calc
         try:
             tournament = fetch_tournament(sub['tournament_url'])
         except Exception: