test: add board and postgres safety net

docs/TODO.md

@@ -14,16 +14,16 @@ This is the ordered implementation roadmap following the accepted exhibit model.
 - [x] Track `.gitignore`, `.dockerignore`, and `.env.example`; confirm that secrets and generated artifacts cannot enter Git accidentally.
 - [x] Commit the current working POC and tag the checkpoint `poc-pre-exhibit-model`.
 - [x] Confirm `main` is pushed to the Ramanujan-hosted `origin` repository.
-- [ ] Keep `npm run build` green and make `npm test` run real tests rather than an empty suite.
+- [x] Keep `npm run build` green and make `npm test` run real tests rather than an empty suite.
 
 ## Milestone 1: focused safety net
 
-- [ ] Test screen/board coordinate conversion across pan and zoom levels.
-- [ ] Test timeline date-to-pixel projection and recomputation after viewport resizing.
+- [x] Test screen/board coordinate conversion across pan and zoom levels.
+- [x] Test timeline date-to-pixel projection and recomputation after viewport resizing.
 - [ ] Test the interaction boundary between exhibit dragging, hand-tool panning, and board-only pinch zoom.
-- [ ] Test folder open/close behavior, retained file positions, and containment bands.
+- [x] Test folder open/close behavior and retained file positions; add visual coverage for containment bands with the browser smoke test.
 - [ ] Test document upload, metadata persistence, board save/reload, and reset.
-- [ ] Run migrations and API integration tests against disposable PostgreSQL, not SQLite or mocked persistence.
+- [x] Run migrations and API integration tests against disposable PostgreSQL, not SQLite or mocked persistence.
 - [ ] Add one browser smoke test: open a level, drag an exhibit, zoom, open a folder, move a file, reload, and verify persistence.
 
 ## Milestone 2: exhibit-schema cutover