Added complete task management functionality including:
- CRUD operations for tasks (create, read, update, delete)
- Task model with status (pending/in_progress/completed) and priority (low/medium/high)
- SQLite database with SQLAlchemy ORM
- Alembic migrations for database schema
- Pydantic schemas for request/response validation
- FastAPI routers with proper error handling
- Filtering and pagination support
- Health check endpoint
- CORS configuration
- Comprehensive API documentation
- Proper project structure following FastAPI best practices
