## Completed Implementation ### Changes Made 1. **Added dependencies** (pyproject.toml:11-14): - sqlalchemy>=2.0.0 - aiosqlite>=0.20.0 - alembic>=1.14.0 - greenlet>=3.0.0 2. **Created SQLAlchemy models** (app/db/models.py): - Rack: id, name, total_units=42 - Device: id, name, rack_id, rack_position, height_units, description - DeviceOutlet: id, device_id, outlet_id - PowerReading: id, timestamp, device_outlet_id, current, voltage, power 3. **Set up database infrastructure**: - app/db/base.py - SQLAlchemy declarative base - app/db/session.py - Async session management - app/config.py - Added database_url setting 4. **Initialized Alembic migrations**: - alembic.ini and alembic/env.py configured for async - Initial migration creates all 4 tables 5. **Added 17 tests** (tests/test_database.py): - CRUD operations for all models - Relationship and cascade delete tests ### Verification - alembic upgrade head runs successfully - All 39 tests pass (17 new + 22 existing) - No deprecation warnings