feat: OpenCode Go usage monitor — hybrid collector + 246-centric dashboard

- usage_collector.py v3.0: HTTP+stored cookies (primary) + CDP (bonus)
  - Cookie keepalive: captures Set-Cookie from responses, saves back to JSON
  - Per-metric regex for SSR parsing (handles nested \[N]={...} structure)
  - Cache merge: preserves other accounts' data on partial collection
- extract_cookies.py: one-time CDP /cookies endpoint → per-account JSON
- dashboard.py: /api/usage reads local file (no Windows bot dependency)
  - /api/usage/refresh: local subprocess collector
  - Auto-timer: 5min background thread (cookie keepalive + fresh data)
- xmpp_agent_core.py: /usage endpoint + auto-timer (for local testing)
- dashboard.html: usage-monitor section (4 cards × 3 metrics + alerts)
- accounts.json: 4 accounts configured (key1-4, gitignored)
- .gitignore: cookies/, accounts.json, usage_stats.json

gateway/scripts/dashboard.py

@@ -9,7 +9,7 @@ Flask app on :5803. Monitors agents across platforms via:
 
 Auto-recovery: restarts local Windows agents after 3 consecutive offline checks.
 """
-import os, sys, re, json, time, subprocess, logging, urllib.request, sqlite3, shutil
+import os, sys, re, json, time, subprocess, logging, urllib.request, sqlite3, shutil, threading
 from pathlib import Path
 from datetime import datetime, timedelta
 from flask import Flask, jsonify, request, send_from_directory
@@ -1032,6 +1032,85 @@ def api_rdp_toggle():
         return jsonify({"ok": False, "error": str(e)})
 
 
+# ════════════════════════════════════════════════════════════
+#  OpenCode Go Usage Monitor — 4个账号用量配额监控 (246 本地采集)
+#  See gateway/scripts/specs/usage_monitor.json
+# ════════════════════════════════════════════════════════════
+_USAGE_STATS_FILE = TEMP_DIR / "usage_stats.json"
+_USAGE_COLLECTOR_SCRIPT = _SCRIPT_DIR / "usage_collector.py"
+_usage_collector_running = False
+
+@app.route("/api/usage")
+def api_usage():
+    """直读本地 usage_stats.json（秒级响应，不依赖 Windows bot）"""
+    if not _USAGE_STATS_FILE.exists():
+        return jsonify({"ok": False, "error": "no data yet (collect never ran)",
+                        "last_refresh_iso": None, "accounts": []})
+    try:
+        with open(str(_USAGE_STATS_FILE), "r", encoding="utf-8") as f:
+            return jsonify(json.load(f))
+    except Exception as e:
+        return jsonify({"ok": False, "error": f"read failed: {e}", "accounts": []})
+
+
+@app.route("/api/usage/refresh", methods=["POST"])
+def api_usage_refresh():
+    """触发本地采集（异步 subprocess，立即返回）"""
+    global _usage_collector_running
+    if _usage_collector_running:
+        return jsonify({"ok": True, "message": "collection already in-flight"})
+    _usage_collector_running = True
+
+    def _runner():
+        global _usage_collector_running
+        try:
+            log.info("usage: starting local collector subprocess")
+            proc = subprocess.run(
+                [sys.executable, str(_USAGE_COLLECTOR_SCRIPT)],
+                capture_output=True, text=True, timeout=120)
+            log.info(f"usage: collector done (rc={proc.returncode}, "
+                      f"stdout={len(proc.stdout)}, stderr={len(proc.stderr)})")
+            if proc.returncode != 0 and proc.stderr:
+                log.warning(f"usage_collector stderr:\n{proc.stderr[-1000:]}")
+        except Exception as e:
+            log.error(f"usage: collector crash: {e}")
+        finally:
+            _usage_collector_running = False
+
+    t = threading.Thread(target=_runner, name="usage_collector", daemon=True)
+    t.start()
+    return jsonify({"ok": True, "message": "collection triggered (~10s), poll /api/usage shortly"})
+
+
+# ── Auto-collect timer (every 5 min, keeps cookies alive) ──
+_USAGE_AUTO_INTERVAL = 300
+
+def _start_usage_auto_timer():
+    """后台线程：每 5 分钟自动采集 + cookie 保活。246 自足，不依赖 Windows。"""
+    def _loop():
+        time.sleep(15)  # initial delay: let dashboard stabilize
+        while True:
+            try:
+                global _usage_collector_running
+                if not _usage_collector_running:
+                    _usage_collector_running = True
+                    proc = subprocess.run(
+                        [sys.executable, str(_USAGE_COLLECTOR_SCRIPT)],
+                        capture_output=True, text=True, timeout=120)
+                    log.info(f"usage auto-timer: rc={proc.returncode}")
+                    if proc.returncode != 0 and proc.stderr:
+                        log.warning(f"usage auto-timer stderr:\n{proc.stderr[-800:]}")
+                    _usage_collector_running = False
+            except Exception as e:
+                log.error(f"usage auto-timer error: {e}")
+                _usage_collector_running = False
+            time.sleep(_USAGE_AUTO_INTERVAL)
+
+    t = threading.Thread(target=_loop, name="usage_auto_timer", daemon=True)
+    t.start()
+    log.info(f"usage auto-timer started (interval={_USAGE_AUTO_INTERVAL}s)")
+
+
 # ════════════════════════════════════════════════════════════
 #  Module Spec — 功能模块 co-located 文档
 # ════════════════════════════════════════════════════════════
@@ -1164,6 +1243,7 @@ def main():
     port = int(os.environ.get("DASHBOARD_PORT", 5803))
     log.info(f"Dashboard starting on :{port}")
     print(f"[dashboard] Starting on http://127.0.0.1:{port}")
+    _start_usage_auto_timer()
     app.run(host="0.0.0.0", port=port, debug=False, use_reloader=False, threaded=True)