Improve V2 mobile navigation, chat, and workspace documents

[Paul Lizer (paullizer)]

Summary

• Permanent global and workspace rails squeezed phone chat input and document browsing. Below 768px, navigation now opens from the shared header and workspace sections use a disclosure, leaving the existing page full-width when closed.
• Reuse the same components, handlers, scope APIs, and permission boundaries. Chat keeps attachment, voice, and Send/Stop together; secondary tools and document view options expand on demand. Document rows prioritize readable names, status, and selection.
• Preserve desktop navigation and document preferences across resizing. Add focus handling, mobile touch targets, dynamic viewport/safe-area support, and responsive regression coverage without separate mobile routes or dependencies.

Linked issue

N/A. No tracking issue was requested.

Release Notes & Latest Features

• New Feature
• Bug Fix
• UI Enhancement
• Breaking Change
• Internal only

Is this visible to end users?

• Yes
• No

Is this admin-facing (Admin Settings, governance, deployment, config)?

• Yes
• No

Should this become a Latest Feature card?

• Yes
• No
• Already added

Screenshot needed for the card?

• Yes
• No
• Attached

Version bump

• application/single_app/config.py VERSION third segment bumped, or not needed because this is docs-only
• deployers/version.txt bumped, or not needed because deployers/ was not changed

Application version: 0.261.322 -> 0.261.323. No deployer changes.

Testing / validation

• npm --prefix .\application\v2_ui run build -- --outDir ..\..\ui_tests\artifacts\orchestration-plan-editor and npm --prefix .\application\v2_ui run build: passed TypeScript and production builds; existing large-bundle warning remains.
• python -m pytest .\ui_tests\test_v2_mobile_navigation.py .\ui_tests\test_v2_mobile_chat_layout.py .\ui_tests\test_v2_mobile_workspace_documents.py .\ui_tests\test_v2_sidebar_conversation_scroll.py::test_the_phone_drawer_holds_search_under_new_chat -q --maxfail=2: 23 passed, including enlarged text, classification banner, phone widths, focus return, all three document scopes, and desktop preference preservation.
• python -m pytest .\ui_tests\test_v2_mobile_navigation.py .\ui_tests\test_v2_mobile_chat_layout.py .\ui_tests\test_v2_mobile_workspace_documents.py .\ui_tests\test_v2_sidebar_conversation_scroll.py::test_the_phone_drawer_holds_search_under_new_chat .\ui_tests\test_v2_group_documents.py::test_document_layout .\ui_tests\test_v2_public_documents.py::test_document_layout -q --maxfail=3: 29 passed, one outdated fixed-row-count assertion failed. Replaced that assertion with touch-target and available-space capacity checks; the final focused command above passes. All 8 group/public document layout cases passed.
• $env:PYTHONPATH = (Resolve-Path .\ui_tests\fixtures).Path; python -m pytest .\ui_tests\test_v2_group_classic_handoffs.py::test_classic_cleanup_layout .\ui_tests\test_v2_shared_workspace_overview_counts.py::test_overview_shows_available_resource_totals -q --maxfail=2: 12 passed. Legacy fixture imports require that path for standalone collection.
• python -m pytest .\functional_tests\test_v2_mobile_layout.py .\functional_tests\test_v2_sidebar_account_menu.py .\functional_tests\test_v2_workspace_sections.py .\functional_tests\test_v2_documents_explorer.py -q --disable-warnings: 40 passed.
• python .\functional_tests\test_docs_app_surface_coverage.py: 7/7 passed. python .\functional_tests\test_docs_site_quality.py: 6/6 passed. git diff --check: passed.
• Reviewed phone and desktop screenshots together. Actual iPhone Safari software-keyboard, browser-chrome, and home-indicator behavior was not tested on a real device; Chromium emulation does not certify it.
• An existing conversation-drawer source test expects a bootstrap gate in route_backend_v2.py that is also absent at HEAD. No backend code was changed to address that unrelated baseline failure.

Documentation

• Release notes updated, or not needed
• Feature documentation updated, or not needed
• Fix documentation updated, or not needed

Release notes left unchanged pending the user's decision. Updated V2 shell/workspace/document feature notes and chat-control reference; added docs/guides/v2-mobile.md and docs/explanation/fixes/V2_MOBILE_LAYOUT_FIX.md. Regenerated inventory has no substantive surface differences.

Security checklist

• New Flask routes include @swagger_route(security=get_auth_security())
• Settings sent to non-admin frontends use sanitize_settings_for_user()
• Browser JavaScript is served from local SimpleChat static assets only; no CDN-hosted JS
• No secrets, keys, connection strings, or local-only artifacts are included

No new Flask routes or settings-response changes. Browser test artifacts and compiled assets remain ignored.