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.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "future-oss"
-version = "1.0.0"
+version = "1.2.0"
 description = "Future OSS - 一切皆为插件的开发者工具运行时框架"
 requires-python = ">=3.10"
 dependencies = [
@@ -15,3 +15,6 @@ dependencies = [
 
 [project.scripts]
 oss = "oss.cli:main"
+
+[tool.setuptools.packages.find]
+include = ["oss*"]