feat: add Docker Compose development stack (#24)

- Add docker-compose.yml with PostgreSQL 15 and Redis 7
- Add health checks for both services
- Add optional dev tools (Adminer, RedisInsight) via 'tools' profile
- Create .env.example with all configuration variables
- Update README.md with Docker setup documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -120,15 +120,49 @@ cp .env.example .env
 # Edit .env with your API keys
 
 # Start infrastructure (PostgreSQL, Redis)
-docker-compose up -d
+docker compose up -d
+
+# Wait for services to be healthy
+docker compose ps
 
 # Install Python dependencies
 pip install -e .
 
+# Run database migrations
+alembic upgrade head
+
 # Run the tracker
 python -m src.main
 ```
 
+### Docker Services
+
+The development stack includes:
+
+| Service | Port | Description |
+|---------|------|-------------|
+| PostgreSQL 15 | 5432 | Primary database |
+| Redis 7 | 6379 | Caching and pub/sub |
+| Adminer | 8080 | Database admin UI (optional) |
+| RedisInsight | 5540 | Redis admin UI (optional) |
+
+```bash
+# Start core services only
+docker compose up -d
+
+# Start with development tools (Adminer, RedisInsight)
+docker compose --profile tools up -d
+
+# View logs
+docker compose logs -f
+
+# Stop all services
+docker compose down
+
+# Stop and remove volumes (reset data)
+docker compose down -v
+```
+
 ### Configuration
 
 ```bash