feat: implement comprehensive logging system with tauri-plugin-log

- Add tauri-plugin-log dependency for structured logging
- Replace tracing with standard log crate throughout Rust backend
- Add model provider configuration loading from config.toml
- Implement ModelStore for frontend model management
- Add configService for centralized configuration handling
- Remove custom logger implementation in favor of tauri-plugin-log
- Update capabilities to include log plugin permissions
- Enhance codex client with provider-specific configuration support

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: milisp

bun.lock

@@ -20,6 +20,7 @@
     "@tauri-apps/api": "^2",
     "@tauri-apps/plugin-dialog": "~2",
     "@tauri-apps/plugin-fs": "~2",
+    "@tauri-apps/plugin-log": "~2",
     "@tauri-apps/plugin-opener": "^2",
     "@tauri-apps/plugin-shell": "~2",
     "@types/diff": "^8.0.0",