Polish change detection density

docs/CODEX_EXECUTION_LOG.md

@@ -3143,3 +3143,31 @@ Limitations:
 
 Next recommended pass:
 - Continue with Change Detection panel hierarchy and analysis workspace balance after this pass is deployed and visually checked.
+
+## Sprint 87 Change Detection density polish (2026-06-20)
+
+Changed:
+- Wrapped Change Detection input controls in `change-detection-input-surface`.
+- Replaced loose error/empty text with shared `result-state` cards inside `change-detection-state-stack`.
+- Wrapped result metrics in `change-detection-result-surface`.
+- Wrapped warning output in `change-detection-warning-surface`.
+- Added compact responsive CSS contracts for Change Detection form and summary grids.
+- Added `backend/tests/test_sprint87_change_detection_density.py`.
+- Updated `frontend/README.md`, `docs/TODO.md` and `CHANGELOG.md`.
+
+Tested:
+- Live browser pre-check attempt against `http://192.168.10.150:1202` hit a transient browser automation click timeout on the QA/QC workspace nav; source review showed Change Detection was still the older header/form/summary stack.
+- Red step: `python -m pytest backend/tests/test_sprint87_change_detection_density.py -q` failed on missing Change Detection surface and density CSS contracts.
+- `python -m pytest backend/tests/test_sprint87_change_detection_density.py backend/tests/test_sprint18_change_detection.py backend/tests/test_sprint39_frontend_orchestration_hooks.py backend/tests/test_sprint86_quality_workspace_density.py backend/tests/test_sprint47_workbench_interaction_smoke.py -q` (`20 passed`)
+- `cd frontend && npm run typecheck`
+- `cd frontend && npm run build`
+- Full readiness and Tower deploy pending in this pass.
+
+Open:
+- None known before full readiness/deploy validation.
+
+Limitations:
+- Frontend Change Detection presentation hierarchy only; no change-detection behavior, API contract, persistence, migration, provider fetching or AI/model changes.
+
+Next recommended pass:
+- Continue with AI Labs run-form hierarchy and detection/segmentation result density after this pass is deployed and visually checked.

docs/TODO.md

@@ -76,6 +76,7 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Add Data workspace selected-summary and panel density polish.
 - [x] Add Map workspace panel hierarchy and layer-control density polish.
 - [x] Add QA/QC workspace result hierarchy and filter density polish.
+- [x] Add Change Detection panel hierarchy and analysis workspace density polish.
 
 ## Sprint 8 status