Complete spec: Code alignment and documentation cleanup

- Ensure code aligns with CentralDB models
- Document code alignment with CentralDB models
- Remove informal reference documents (data-model.md, DB_API_SPEC.json, GARMINSYNC_SPEC.md)
- Run linters and formatters (black, isort, mypy)
- Update project configuration files
- Add .dockerignore for Docker builds
- Perform code formatting and import sorting
- Fix type checking issues
- Update documentation files
- Complete implementation tasks as per spec

.dockerignore

@@ -0,0 +1,20 @@
+node_modules/
+.git/
+*.log*
+.env*
+coverage/
+__pycache__/
+*.pyc
+.DS_Store
+Thumbs.db
+*.tmp
+*.swp
+.vscode/
+.idea/
+build/
+dist/
+*.egg-info/
+.pytest_cache/
+.mypy_cache/
+.venv/
+venv/