Polish export system density

docs/CODEX_EXECUTION_LOG.md

@@ -3210,3 +3210,38 @@ Limitations:
 
 Next recommended pass:
 - Continue with export/system final visual consistency or live workflow guidance once this pass is deployed and visually checked.
+
+## Sprint 89 Export/System density polish (2026-06-20)
+
+Changed:
+- Wrapped Export Center content in `export-center-shell`.
+- Grouped export summary, handoff readiness, artifact actions, current state cards and history into focused `export-*` surfaces.
+- Wrapped Provider Capabilities content in `system-provider-shell`.
+- Replaced loose provider loading/error/empty text with shared `result-state` cards.
+- Grouped provider registry content into `system-provider-capability-surface`.
+- Split provider limitation/reason text and attribution/license data into `provider-detail-stack` and provenance cards.
+- Added shared Export/System density CSS for compact summary, handoff, action, history and provider provenance grids.
+- Added `backend/tests/test_sprint89_export_system_density.py`.
+- Updated `frontend/README.md`, `docs/TODO.md` and `CHANGELOG.md`.
+
+Tested:
+- Red step: `python -m pytest backend/tests/test_sprint89_export_system_density.py -q` failed on missing Export/System shells, surfaces and CSS contracts.
+- `python -m pytest backend/tests/test_sprint89_export_system_density.py backend/tests/test_sprint51_quality_export_polish.py backend/tests/test_sprint64_export_handoff_polish.py backend/tests/test_sprint76_export_system_mobile_polish.py backend/tests/test_sprint78_export_preview_readability.py -q` (`12 passed`)
+- `cd frontend && npm run typecheck`
+- `cd frontend && npm run build`
+- In-app browser fallback note: the Browser click path timed out on the local workspace navigation CDP command, so rendered validation used local Chrome via Playwright.
+- Local Chrome UI check against `http://127.0.0.1:5174` passed on desktop and mobile: Export/System shells and surfaces rendered with no horizontal overflow. Local console showed expected Vite proxy 500s because only the frontend server was running.
+- `bash scripts/run_readiness_check.sh` (`303 passed`; frontend typecheck/build passed; Alembic head `202606120900`; live smoke syntax passed)
+- Tower deploy via `scripts/deploy_tower.ps1` rebuilt and restarted the all-in-one container on `http://192.168.10.150:1202`.
+- Tower deploy live migration smoke passed with PostGIS `3.6 USE_GEOS=1 USE_PROJ=1 USE_STATS=1` and required runtime schema objects present.
+- Browser runtime verification passed for frontend, proxied API and icon.
+- Live Chrome UI check against `http://192.168.10.150:1202` passed on desktop and mobile: Export/System shells and surfaces rendered, four provider cards and eight provider provenance cards were visible, no horizontal overflow and no console warnings/errors.
+
+Open:
+- None known after full readiness, Tower deploy and live browser validation.
+
+Limitations:
+- Frontend Export/System presentation hierarchy only; no export behavior, API contract, persistence, migration, provider fetching or AI/model changes.
+
+Next recommended pass:
+- Continue with end-to-end workflow guidance after this pass is deployed and visually checked.

docs/TODO.md

@@ -78,6 +78,7 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Add QA/QC workspace result hierarchy and filter density polish.
 - [x] Add Change Detection panel hierarchy and analysis workspace density polish.
 - [x] Add AI Labs Detection/Segmentation hierarchy and result density polish.
+- [x] Add Export/System handoff hierarchy and provider registry density polish.
 
 ## Sprint 8 status