Polish workbench shell density

docs/CODEX_EXECUTION_LOG.md

@@ -2984,3 +2984,30 @@ Limitations:
 
 Next recommended pass:
 - Continue with visual density review for topbar/sidebar/responsive shell after another live browser pass.
+
+## Sprint 82 Shell density polish (2026-06-20)
+
+Changed:
+- Added a keyboard skip link that targets the active workspace main region.
+- Added an explicit `Primary workspaces` label to the sidebar navigation and a focusable `workspace-main` target.
+- Tightened narrow-screen topbar, context chip, sidebar nav and workspace shortcut density while keeping intentional horizontal rails scroll-safe.
+- Added `backend/tests/test_sprint82_shell_density_polish.py`.
+- Updated `frontend/README.md`, `docs/TODO.md` and `CHANGELOG.md`.
+
+Tested:
+- Live browser pre-check against `http://192.168.10.150:1202` showed no console errors, no horizontal document overflow and a too-tall narrow viewport topbar/context stack.
+- Red step: `python -m pytest backend/tests/test_sprint82_shell_density_polish.py -q` failed on missing skip-link, main focus target and compact mobile shell CSS contracts.
+- `python -m pytest backend/tests/test_sprint82_shell_density_polish.py -q` (`3 passed`)
+- `python -m pytest backend/tests/test_sprint82_shell_density_polish.py backend/tests/test_sprint79_accessibility_focus_polish.py backend/tests/test_sprint72_mobile_overflow_hardening.py backend/tests/test_sprint49_workbench_shell_refactor.py backend/tests/test_sprint47_workbench_interaction_smoke.py -q` (`13 passed`)
+- `cd frontend && npm run typecheck`
+- `cd frontend && npm run build`
+- `bash scripts/run_readiness_check.sh` (`279 passed`; frontend typecheck/build passed; Alembic single head `202606120900`)
+
+Open:
+- Deployment and live browser verification still need to run for this pass.
+
+Limitations:
+- Frontend shell presentation/accessibility polish only; no workflow behavior, API contract, persistence, migration, provider fetching or AI/model changes.
+
+Next recommended pass:
+- Continue with a live visual review of dense workspace panel hierarchy after the shell density changes are deployed.

docs/TODO.md

@@ -71,6 +71,7 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Add accessibility focus polish for primary workbench keyboard navigation.
 - [x] Add raster/vector operation form readability polish for dense tool panels.
 - [x] Add compact loading/error/empty/result state polish across QA, exports and AI labs.
+- [x] Add compact shell density polish for topbar context, mobile navigation and workspace skip flow.
 
 ## Sprint 8 status