Goals table has selected_task_id referencing tasks(id) without
ON DELETE SET NULL. When deleting a task, first clear any
selected_task_id references in goals to prevent FK violation.
Also update schema for future databases.
Use INSERT OR IGNORE instead of SELECT-then-INSERT for
default admin user creation, avoiding the race condition
when multiple gunicorn workers initialize simultaneously.
- Implement notes database schema and API endpoints
- Add notes page with filtering, search, and markdown support
- Persist selected goal and task preferences for better UX
- Include responsive design and mobile-friendly layout
- Replace TinyDB (JSON file) with sqlite3 for data persistence
- Add schema.py: table creation + data migration from db.json
- Rewrite database.py: all CRUD operations use sqlite3 directly
- All data retains original IDs via migration script
- Remove tinydb dependency from pyproject.toml
