feat: implement plugin architecture and application settings with Svelte UI

- Added plugin base and loader for backend extensibility
- Implemented application settings management with config persistence
- Created Svelte-based frontend with Dashboard and Settings pages
- Added API routes for plugins, tasks, and settings
- Updated documentation and specifications
- Improved project structure and developer tools

.kilocode/rules/specify-rules.md

@@ -9,8 +9,8 @@ Auto-generated from all feature plans. Last updated: 2025-12-19
 ## Project Structure
 
 ```text
-backend/
-frontend/
+backend/
+frontend/
 tests/
 ```