Add monitoring, metrics tracking, and enhanced logging

- Add BotMonitor class for tracking requests, errors, and health status
- Track request success/failure, response times, error rates
- Add !status command (admin) for detailed metrics with embed
- Add !health command (anyone) for quick health check
- Add rotating file logging support (LOG_FILE config)
- Auto-detect unhealthy status when errors exceed threshold
- Record errors with timestamps and context for debugging

.env.example

@@ -62,7 +62,19 @@ SEARXNG_ENABLED=true
 SEARXNG_MAX_RESULTS=5
 
 # ===========================================
-# Logging
+# Logging & Monitoring
 # ===========================================
 # Log level: DEBUG, INFO, WARNING, ERROR
 LOG_LEVEL=INFO
+
+# Log file path (optional - logs to console only if not set)
+# LOG_FILE=logs/bot.log
+
+# Custom log format (optional)
+# LOG_FORMAT=%(asctime)s - %(name)s - %(levelname)s - %(message)s
+
+# ===========================================
+# Monitoring Commands
+# ===========================================
+# Use !status (admin only) for detailed metrics
+# Use !health (anyone) for quick health check