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

frontend/src/main.js

@@ -1,9 +1,17 @@
+// [DEF:main:Module]
+// @SEMANTICS: entrypoint, svelte, init
+// @PURPOSE: Entry point for the Svelte application.
+// @LAYER: UI-Entry
+
 import './app.css'
 import App from './App.svelte'
 
+// [DEF:app_instance:Data]
+// @PURPOSE: Initialized Svelte app instance.
 const app = new App({
   target: document.getElementById('app'),
   props: {}
 })
 
 export default app
+// [/DEF:main]