Improve quality and export usability layout

docs/CODEX_EXECUTION_LOG.md

@@ -1,3 +1,29 @@
+## Sprint 115 QA/QC and Exports usability layout pass (2026-07-04)
+
+Changed:
+- Added a QA/Exports usability layer to the frontend shell CSS to reduce evidence/history density without changing behavior.
+- Rebalanced QA/QC and Exports workspace columns for review-first usage.
+- Made QA/QC summary, handoff, drilldown, feature evidence, metric history and raw provenance surfaces more compact.
+- Reduced raw QA provenance height so JSON evidence remains available but no longer dominates the page.
+- Made export handoff cards, latest-artifact cards, action cards and export history controls denser and easier to scan.
+- Updated `CHANGELOG.md`, `docs/TODO.md` and `frontend/README.md`.
+- Added regression coverage in `backend/tests/test_sprint115_quality_export_usability_layout.py`.
+
+Validation:
+- `cd frontend && npm run typecheck` passed.
+- `cd frontend && npm run build` passed.
+- `python -m pytest backend\tests\test_sprint115_quality_export_usability_layout.py backend\tests\test_sprint86_quality_workspace_density.py backend\tests\test_sprint89_export_system_density.py backend\tests\test_sprint70_quality_handoff_polish.py backend\tests\test_sprint78_export_preview_readability.py -q` passed: 15 tests.
+- `python -m compileall backend/app` passed.
+- `cd backend && python -m pytest -q` passed: 362 tests.
+- `bash scripts/run_readiness_check.sh` passed: 362 backend tests plus frontend typecheck/build.
+
+Limitations:
+- This pass is visual/layout only; it does not change API contracts, persistence, export generation, QA metrics or map behavior.
+- Live Tower redeploy still needs to be run after commit/push before the user sees this pass at `http://192.168.10.150:1202`.
+
+Next recommended pass:
+- Run a live visual audit after redeploy, then refine AI Labs/System or address any remaining visual rough edges found in the browser.
+
 ## Sprint 114 Data and Map usability layout pass (2026-07-04)
 
 Changed: