feat: implement list ownership and access control

- Modified createList to assign ownerId to authenticated user
- Updated getLists to filter by user access (owner or collaborator)
- Added ownership checks to updateList (owner or editor can update)
- Added ownership checks to deleteList (only owner can delete)
- Implemented access control for all item operations (create, update, delete, toggle)
- Updated getItem, searchItems, and getItemsByFilter to enforce access control
- Added dynamic rendering to pages that use authentication
- Cascade deletion already handled by database schema (onDelete: Cascade)

Requirements: 4.1, 4.2, 4.3, 4.5

.kiro/specs/user-auth-and-sharing/tasks.md

@@ -96,7 +96,7 @@
   - Redirect unauthenticated users to login
   - _Requirements: 3.3, 3.5_
 
-- [ ] 8. Update list operations for ownership
+- [x] 8. Update list operations for ownership
   - Modify createList to assign ownerId
   - Update getLists to filter by user access
   - Add ownership checks to updateList and deleteList