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>

swiss_calc/parser.py

@@ -334,16 +334,47 @@ def extract_tournament_meta(html: str) -> dict:
 
 # ── Full tournament fetch ─────────────────────────────────────
 
+def _normalize_url(url: str) -> str:
+    base = re.sub(r'[&?]art=\d+', '', url)
+    base = re.sub(r'[&?]rd=\d+', '', base)
+    base = re.sub(r'[&?]turdet=\w+', '', base)
+    base = re.sub(r'[&?]SNode=\w+', '', base)
+    return base
+
+
+def fetch_tournament_quick(url: str) -> dict:
+    """Lightweight change-detection fetch: only art=4 (1 HTTP request).
+
+    Returns standings from the page directly (no art=2 cross-reference).
+    Use to check if results_count or current_round changed before doing a
+    full fetch_tournament() call.
+    """
+    base_url = _normalize_url(url)
+    try:
+        html = fetch_url(base_url + '&art=4&turdet=YES')
+    except Exception as e:
+        raise RuntimeError(f'Не удалось загрузить турнир: {e}')
+    meta = extract_tournament_meta(html)
+    standings = parse_standings(html)
+    current_round = meta['current_round']
+    if standings:
+        max_results = max(len(s['results']) for s in standings)
+        if max_results > current_round:
+            current_round = max_results
+    return {
+        'name': meta['name'],
+        'num_rounds': meta['num_rounds'],
+        'current_round': current_round,
+        'standings': standings,
+    }
+
+
 def fetch_tournament(url: str) -> dict:
     """Fetch full tournament data from any chess-results.com URL.
 
     Detects current state automatically (any number of completed rounds).
     """
-    # Normalize URL to base
-    base_url = re.sub(r'[&?]art=\d+', '', url)
-    base_url = re.sub(r'[&?]rd=\d+', '', base_url)
-    base_url = re.sub(r'[&?]turdet=\w+', '', base_url)
-    base_url = re.sub(r'[&?]SNode=\w+', '', base_url)
+    base_url = _normalize_url(url)
 
     # Fetch standings
     standings_url = base_url + '&art=4&turdet=YES'