feat(metrics): add comprehensive metrics collection system

Implement real-time stats tracking including connection counts, request metrics, bandwidth usage, and route-specific monitoring. Adds MetricsCollector with observable streams for reactive monitoring integration.

ts/proxies/smart-proxy/models/index.ts

@@ -4,3 +4,4 @@
 // Export everything except IAcmeOptions from interfaces
 export type { ISmartProxyOptions, IConnectionRecord, TSmartProxyCertProvisionObject } from './interfaces.js';
 export * from './route-types.js';
+export * from './metrics-types.js';

ts/proxies/smart-proxy/models/metrics-types.ts

@@ -0,0 +1,54 @@
+/**
+ * Interface for proxy statistics and metrics
+ */
+export interface IProxyStats {
+  /**
+   * Get the current number of active connections
+   */
+  getActiveConnections(): number;
+  
+  /**
+   * Get connection counts grouped by route name
+   */
+  getConnectionsByRoute(): Map<string, number>;
+  
+  /**
+   * Get connection counts grouped by IP address
+   */
+  getConnectionsByIP(): Map<string, number>;
+  
+  /**
+   * Get the total number of connections since proxy start
+   */
+  getTotalConnections(): number;
+  
+  /**
+   * Get the current requests per second rate
+   */
+  getRequestsPerSecond(): number;
+  
+  /**
+   * Get total throughput (bytes transferred)
+   */
+  getThroughput(): { bytesIn: number; bytesOut: number };
+}
+
+/**
+ * Extended interface for additional metrics helpers
+ */
+export interface IProxyStatsExtended extends IProxyStats {
+  /**
+   * Get throughput rate (bytes per second) for last minute
+   */
+  getThroughputRate(): { bytesInPerSec: number; bytesOutPerSec: number };
+  
+  /**
+   * Get top IPs by connection count
+   */
+  getTopIPs(limit?: number): Array<{ ip: string; connections: number }>;
+  
+  /**
+   * Check if an IP has reached the connection limit
+   */
+  isIPBlocked(ip: string, maxConnectionsPerIP: number): boolean;
+}