Title: Implement minimal core framework with PL injection and update build config

Key features implemented:
- Updated package metadata and dependencies in PKG-INFO, setup files
- Added main.py entry point for backward compatibility with README launch method
- Enhanced CLI with config options, system info command, and proper signal handling
- Implemented minimal PluginManager loading only plugin-loader core plugin
- Refactored PluginLoader to follow minimal core design, removed sandbox/isolation complexity
- Updated auto-dependency plugin with safer PL injection mechanism and disabled pl_injection
- Removed legacy plugin files (firewall, frp_proxy, ftp_server, multi_lang_deploy, ops_toolbox, security_gateway) as functionality moved to core plugin system
- Improved gitignore with comprehensive ignore patterns

The changes implement a minimal core framework design where only the plugin-loader is directly loaded by the core, with all other plugins managed through the PL injection mechanism, significantly simplifying the architecture.

oss.config.json

@@ -0,0 +1,10 @@
+{
+    "HTTP_API_PORT": 8080,
+    "HTTP_TCP_PORT": 8082,
+    "HOST": "0.0.0.0",
+    "DATA_DIR": "./data",
+    "STORE_DIR": "./store",
+    "LOG_LEVEL": "INFO",
+    "PERMISSION_CHECK": true,
+    "MAX_WORKERS": 4
+}