feat: Implement Provider Tabs in Settings View

- Added a new `ProviderTabs` component to manage different AI providers (Claude and Cursor) within the settings view.
- Created `ClaudeSettingsTab` and `CursorSettingsTab` components for provider-specific configurations.
- Updated navigation to reflect the new provider structure, replacing the previous Claude-only setup.
- Marked completion of the settings view provider tabs phase in the integration plan.

apps/ui/src/components/views/settings-view/hooks/use-settings-view.ts

@@ -3,6 +3,7 @@ import { useState, useCallback } from 'react';
 export type SettingsViewId =
   | 'api-keys'
   | 'claude'
+  | 'providers'
   | 'ai-enhancement'
   | 'appearance'
   | 'terminal'