Control: Add monitoring server with ETCP protocol support

- Implement control_server.c/h for monitoring and management
- Add Windows-compatible uasync_poll using select() instead of WSAPoll
- Fix Wintun adapter creation to open existing adapters first
- Add debug category for control server operations
- Update build files to include control server in compilation
- Add test_control_server to test suite

lib/debug_config.h

@@ -50,6 +50,7 @@ typedef uint64_t debug_category_t;
 #define DEBUG_CATEGORY_NORMALIZER  ((debug_category_t)1 << 11)  // packet normalizer
 #define DEBUG_CATEGORY_BGP         ((debug_category_t)1 << 12)  // BGP route exchange
 #define DEBUG_CATEGORY_SOCKET      ((debug_category_t)1 << 13)  // Socket operations
+#define DEBUG_CATEGORY_CONTROL     ((debug_category_t)1 << 14)  // Control/monitoring server
 #define DEBUG_CATEGORY_ALL         ((debug_category_t)0xFFFFFFFFFFFFFFFFULL)
 
 /* Debug configuration structure */