feat: add config directory override support for WSL

- Add persistent app settings with custom Claude Code and Codex config directories
- Add config directory override UI in settings modal with manual input, browse, and reset options
- Integrate tauri-plugin-dialog for native directory picker
- Support WSL and other special environments where config paths need manual specification

Changes:
- settings.rs: Implement settings load/save and directory override logic
- SettingsModal: Add config directory override UI components
- API: Add get_config_dir and pick_directory commands

src-tauri/src/codex_config.rs

@@ -10,6 +10,10 @@ use std::path::Path;
 
 /// 获取 Codex 配置目录路径
 pub fn get_codex_config_dir() -> PathBuf {
+    if let Some(custom) = crate::settings::get_codex_override_dir() {
+        return custom;
+    }
+
     dirs::home_dir().expect("无法获取用户主目录").join(".codex")
 }