feat(monitor): add real-time monitoring dashboard with Redis persistence

Complete observability solution for production deployments with terminal-style UI.

**Backend Implementation:**
- `monitor.py`: Stats manager tracking requests, browsers, errors, timeline data
- `monitor_routes.py`: REST API endpoints for all monitor functionality
  - GET /monitor/health - System health snapshot
  - GET /monitor/requests - Active & completed requests
  - GET /monitor/browsers - Browser pool details
  - GET /monitor/endpoints/stats - Aggregated endpoint analytics
  - GET /monitor/timeline - Time-series data (memory, requests, browsers)
  - GET /monitor/logs/{janitor,errors} - Event logs
  - POST /monitor/actions/{cleanup,kill_browser,restart_browser} - Control actions
  - POST /monitor/stats/reset - Reset counters
- Redis persistence for endpoint stats (survives restart)
- Timeline tracking (5min window, 5s resolution, 60 data points)

**Frontend Dashboard** (`/dashboard`):
- **System Health Bar**: CPU%, Memory%, Network I/O, Uptime
- **Pool Status**: Live counts (permanent/hot/cold browsers + memory)
- **Live Activity Tabs**:
  - Requests: Active (realtime) + recent completed (last 100)
  - Browsers: Detailed table with actions (kill/restart)
  - Janitor: Cleanup event log with timestamps
  - Errors: Recent errors with stack traces
- **Endpoint Analytics**: Count, avg latency, success%, pool hit%
- **Resource Timeline**: SVG charts (memory/requests/browsers) with terminal aesthetics
- **Control Actions**: Force cleanup, restart permanent, reset stats
- **Auto-refresh**: 5s polling (toggleable)

**Integration:**
- Janitor events tracked (close_cold, close_hot, promote)
- Crawler pool promotion events logged
- Timeline updater background task (5s interval)
- Lifespan hooks for monitor initialization

**UI Design:**
- Terminal vibe matching Crawl4AI theme
- Dark background, cyan/pink accents, monospace font
- Neon glow effects on charts
- Responsive layout, hover interactions
- Cross-navigation: Playground ↔ Monitor

**Key Features:**
- Zero-config: Works out of the box with existing Redis
- Real-time visibility into pool efficiency
- Manual browser management (kill/restart)
- Historical data persistence
- DevOps-friendly UX

Routes:
- API: `/monitor/*` (backend endpoints)
- UI: `/dashboard` (static HTML)

deploy/docker/server.py

@@ -16,6 +16,7 @@ from fastapi import Request, Depends
 from fastapi.responses import FileResponse
 import base64
 import re
+import logging
 from crawl4ai import AsyncWebCrawler, BrowserConfig, CrawlerRunConfig
 from api import (
     handle_markdown_request, handle_llm_qa,
@@ -112,15 +113,40 @@ AsyncWebCrawler.arun = capped_arun
 @asynccontextmanager
 async def lifespan(_: FastAPI):
     from crawler_pool import init_permanent
+    from monitor import MonitorStats
+    import monitor as monitor_module
+
+    # Initialize monitor
+    monitor_module.monitor_stats = MonitorStats(redis)
+    await monitor_module.monitor_stats.load_from_redis()
+
+    # Initialize browser pool
     await init_permanent(BrowserConfig(
         extra_args=config["crawler"]["browser"].get("extra_args", []),
         **config["crawler"]["browser"].get("kwargs", {}),
     ))
+
+    # Start background tasks
     app.state.janitor = asyncio.create_task(janitor())
+    app.state.timeline_updater = asyncio.create_task(_timeline_updater())
+
     yield
+
+    # Cleanup
     app.state.janitor.cancel()
+    app.state.timeline_updater.cancel()
     await close_all()
 
+async def _timeline_updater():
+    """Update timeline data every 5 seconds."""
+    from monitor import get_monitor
+    while True:
+        await asyncio.sleep(5)
+        try:
+            await get_monitor().update_timeline()
+        except Exception as e:
+            logger.warning(f"Timeline update error: {e}")
+
 # ───────────────────── FastAPI instance ──────────────────────
 app = FastAPI(
     title=config["app"]["title"],
@@ -138,6 +164,16 @@ app.mount(
     name="play",
 )
 
+# ── static monitor dashboard ────────────────────────────────
+MONITOR_DIR = pathlib.Path(__file__).parent / "static" / "monitor"
+if not MONITOR_DIR.exists():
+    raise RuntimeError(f"Monitor assets not found at {MONITOR_DIR}")
+app.mount(
+    "/dashboard",
+    StaticFiles(directory=MONITOR_DIR, html=True),
+    name="monitor_ui",
+)
+
 
 @app.get("/")
 async def root():
@@ -221,6 +257,12 @@ def _safe_eval_config(expr: str) -> dict:
 # ── job router ──────────────────────────────────────────────
 app.include_router(init_job_router(redis, config, token_dep))
 
+# ── monitor router ──────────────────────────────────────────
+from monitor_routes import router as monitor_router
+app.include_router(monitor_router)
+
+logger = logging.getLogger(__name__)
+
 # ──────────────────────── Endpoints ──────────────────────────
 @app.post("/token")
 async def get_token(req: TokenRequest):