feat(frpLogger): add real-time instance log streaming functionality

Implement cross-platform log streaming for frpc instances with support for Windows, systemd, and init.d systems. Includes WebSocket API endpoint for real-time log streaming, token validation, and instance ownership checks. Update README and API documentation to reflect new functionality.

The implementation handles:
- Platform-specific log collection (Windows Event Log, journalctl, log files)
- WebSocket-based real-time streaming
- Token validation and instance access control
- Log level parsing and formatting
- Historical log retrieval since service start

session.go

@@ -331,3 +331,18 @@ func ListActiveSessions() []*Session {
 	}
 	return activeSessions
 }
+
+func ValidateTokenFromMap(token string) (int, error) {
+	tokenMux.RLock()
+	defer tokenMux.RUnlock()
+
+	for userID, tokenInfo := range tokenMap {
+		if tokenInfo.Token == token {
+			if time.Since(tokenInfo.CreatedAt) > tokenTTL {
+				return 0, fmt.Errorf("token expired")
+			}
+			return userID, nil
+		}
+	}
+	return 0, fmt.Errorf("invalid token")
+}