feat: implement core functionality for super-frpc service

This commit introduces the core functionality for the super-frpc service including:
- Configuration management
- User authentication and authorization
- Database integration
- FRPC instance management
- API endpoints for user operations
- Token-based authentication system
- Password hashing and validation

config.json

@@ -0,0 +1,7 @@
+{
+  "listenAddr": "0.0.0.0",
+  "listenPort": "8080",
+  "frpcPath": "/usr/bin/frpc",
+  "instancePath": "./configs",
+  "debug": false
+}