Fix inconsistent modal overlays by migrating all custom implementations
to the unified shadcn/ui Dialog component with proper z-index layering.
Changes:
- Update Dialog component to support three z-index levels:
- base (z-40): First-level dialogs
- nested (z-50): Nested dialogs
- alert (z-[60]): Alert/confirmation dialogs (using Tailwind arbitrary value)
- Refactor all custom modal implementations to use Dialog:
- EndpointSpeedTest: API endpoint speed testing panel
- ClaudeConfigEditor: Claude common config editor
- CodexQuickWizardModal: Codex quick setup wizard
- CodexCommonConfigModal: Codex common config editor
- SettingsDialog: Restart confirmation prompt
- Remove custom backdrop implementations and manual z-index
- Leverage Radix UI Portal for automatic DOM order management
- Ensure consistent overlay behavior and keyboard interactions
This eliminates the "background residue" issue where overlays from
different layers would conflict, providing a unified and professional
user experience across all modal interactions.
- Remove unused useDarkMode hook (now using shadcn theme-provider)
- Clean up MCP components (remove redundant code)
- Add restart API to settings
- Minor type improvements
- Migrate all form components from ProviderForm/ to providers/forms/
- Create shared components to eliminate code duplication:
* ApiKeySection: unified API key input with "Get API Key" link
* EndpointField: unified endpoint URL input with manage button
- Refactor ClaudeFormFields (-31% lines) and CodexFormFields (-33% lines)
- Update all import paths to use new locations
- Reduce code duplication from ~12% to ~7%
This change improves maintainability and makes the codebase more DRY.