feat: add subjects and tasks API, hooks, and related types

- Implemented subjects API with functions for creating, updating, and retrieving subjects, including history and bibliography.
- Added tasks API for managing user tasks, including listing and marking tasks as completed.
- Created hooks for managing AI interactions, authentication, subjects, tasks, and metadata queries.
- Established query keys for caching and managing query states.
- Introduced Supabase client and environment variable management for better configuration.
- Defined types for database and domain models to ensure type safety across the application.

package.json

@@ -28,6 +28,7 @@
     "@radix-ui/react-tabs": "^1.1.13",
     "@radix-ui/react-tooltip": "^1.2.8",
     "@stepperize/react": "^5.1.9",
+    "@supabase/supabase-js": "^2.90.1",
     "@tailwindcss/vite": "^4.0.6",
     "@tanstack/react-devtools": "^0.7.0",
     "@tanstack/react-query": "^5.66.5",