Enforce monthly request cap (12000/mo plan) via RapidAPI quota headers; optional MONTHLY_DOWNLOAD_LIMIT self-cap; show quota in health check

app.py

@@ -147,6 +147,13 @@ def check_access():
             if r.status_code == 200:
                 api_ok = True
                 lines.append("- ✅ Download API reachable and key valid (HTTP 200)")
+                downloader_mod._update_quota(r.headers)  # prime the monthly-cap tracker
+                q = downloader_mod.quota_status()
+                if q.get("limit") is not None and q.get("remaining") is not None:
+                    days = (q["reset"] // 86400) if q.get("reset") else "?"
+                    cap = f" · self-cap {q['self_cap']}" if q.get("self_cap") else ""
+                    lines.append(f"- 📊 Monthly requests: **{q['remaining']} / {q['limit']} left** "
+                                 f"({q.get('used', 0)} used, resets in ~{days} days){cap}")
             elif r.status_code in (401, 403):
                 api_ok = False
                 lines.append(f"- ❌ Download API rejected the key (HTTP {r.status_code}) — "