Issue #51: Enforce repository boundary at CI level using import-linter.
Contract 'forbid_router_db_import' checks that app.routers never imports
app.dependencies directly, keeping the DB access path through service
contexts only.
- Add import-linter>=2.0.0 to dev dependencies (backend/pyproject.toml)
- Configure [tool.importlinter] with package_root and root_packages
- Add [[tool.importlinter.contracts]] with type='forbidden', source
app.routers, forbidden app.dependencies
- Add 'Import Boundary' CI job (import-linter)
- Document import-linter in CONTRIBUTING.md code quality table
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>