Add native V2 file source configuration for all workspaces

[Paul Lizer (paullizer)]

Summary

• Remove the personal workspace's classic-page configuration hand-off so file-source setup remains usable when New UI only mode blocks legacy pages. Personal, group and public workspaces now use the shared native editor for the full existing configuration surface.
• Add authorized personal options/single-source reads and optional configuration-revision checks for saves/deletes. Preserve drafts during conflicts, stage credential replacements safely, and retain compatibility with classic callers that omit the revision token.
• Harden editor loading, stale test/browse responses, accessible labels and focus return. Preserve connector availability, workspace permissions, stored-secret behavior, and existing sync/history/document-retention workflows. Add executable API, transport and production-SPA regressions plus versioned documentation.

Linked issue

Refs #1722

Completes row 4 only. The other parity gaps and the companion legacy routing/interface-policy change remain outside this PR.

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

Release notes were left unchanged because approval was unavailable; the feature documentation describes version 0.261.310.

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: 0.261.309 -> 0.261.310. No deployer changes.

Testing / validation

Python commands below used the isolated validation interpreter (Flask 3.1.3/Werkzeug 3.1.6), rather than the incompatible global Flask installation. Fixture suites used PYTHONPATH=ui_tests\fixtures.

• npm --prefix application\v2_ui run typecheck - passed.
• npm --prefix application\v2_ui run build - passed.
• python -m pytest ui_tests\test_v2_personal_file_sources.py ui_tests\test_v2_group_file_sources.py ui_tests\test_v2_public_file_sources.py -q --tb=short --browser chromium --tracing retain-on-failure - 100 passed.
• python -m pytest functional_tests\test_personal_file_source_apis.py functional_tests\test_v2_personal_file_sources.py functional_tests\test_public_file_source_fixture_parity.py functional_tests\test_group_file_source_fixture_parity.py -q --tb=short - 86 passed.
• python -m pytest functional_tests\test_group_file_source_apis.py functional_tests\test_public_file_source_apis.py functional_tests\test_group_file_source_sync_fields.py functional_tests\test_file_source_credential_round_trip_fix.py functional_tests\test_file_sync_concurrent_write_safety.py -q --tb=short - 154 passed.
• python -m pytest functional_tests\test_v2_personal_file_sources.py functional_tests\test_group_file_source_transport.py functional_tests\test_public_file_source_transport.py -q --tb=short - 29 passed.
• python functional_tests\route_tests\test_route_blueprint_policy_inventory.py - 15/15 passed.
• python functional_tests\route_tests\test_route_unauthenticated_policy_contract.py - 10/10 passed.
• python functional_tests\route_tests\test_route_policy_test_coverage.py - 3/3 passed.
• python scripts\build_docs_inventory.py - passed; no semantic inventory change.
• python functional_tests\test_docs_app_surface_coverage.py - 7/7 passed.
• python functional_tests\test_docs_site_quality.py - 6/6 passed.
• python scripts\check_xss_sinks.py application\v2_ui\src\components\ui\Modal.tsx application\v2_ui\src\components\fileSources\FileSourceEditorDialog.tsx application\v2_ui\src\lib\fileSourceFields.ts application\v2_ui\src\lib\fileSourceWorkbench.ts application\v2_ui\src\pages\workspace\FileSourcesSection.tsx application\v2_ui\src\pages\workspace\GroupFileSourcesSection.tsx application\single_app\route_backend_file_sync.py - passed for 7 files.
• python scripts\check_broken_access_control.py application\single_app\route_backend_file_sync.py application\single_app\functions_file_sync.py - passed for 2 files.
• git -c core.whitespace=blank-at-eol,blank-at-eof,space-before-tab,cr-at-eol diff --cached --check - passed.

Desktop-light/mobile-dark captures were inspected, and dialog overflow/focus checks passed. The Impeccable source detector also passed. Live root-hosted/Teams behavior and New UI only enforcement were not tested: they require the companion routing change and a configured deployment.

Documentation

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

Added V2_FILE_SOURCE_CONFIGURATION.md; updated personal/group/public feature notes and the file-sync guide with distinct native V2 and classic workflows. Separate fix documentation is not needed for this feature; release notes remain pending approval.

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

New responses contain only editor-safe options and sanitized source projections, not raw settings, credentials or Key Vault references. Test credentials are synthetic. Identity creation and new/coming-soon connector enablement are not included.