[Paul Lizer (paullizer)]

Summary

• Fix selected-document orchestration failing before its first native read: discovery created a second DocumentSearchPlugin class that the canonical reader safety check correctly rejected.
• Reuse canonical package imports while preserving permissions, selected-source/revision checks, separate plugin instance configuration, cancellation, and existing recovery policy.
• Preserve safe initialization, reader-identity, document-read, and missing-result failures in saved details and hashed telemetry. Replace the misleading loader shortcut with real discovery, cold/concurrent startup coverage, and the complete 81-extension indexed-text matrix.
• Explicitly pin the existing PyMeta3==0.5.1 startup dependency, add the real-loader CI gate, and update documentation/release notes for 0.261.421.

The format matrix covers indexed-text retrieval, not native properties for every accepted upload type. Regenerated release pages preserve all 313 source releases. The repository's FFmpeg pin and pip configuration remain unchanged; the alternate-feed/exact-wheel selection was limited to a temporary local build context. No Azure deployment or live canary was performed.

Linked issue

N/A - the user explicitly requested no associated GitHub issue.

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

Operational startup and support diagnostics only; no new admin controls or settings.

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: 0.261.420 -> 0.261.421. No files under deployers/ changed.

Testing / validation

Fresh PR preflight: passed, 52 tests (warnings emitted).

$env:PYTHONPATH = "$PWD\application\single_app;$PWD\functional_tests"
python -m pytest -q -p no:cacheprovider -p test_support.cosmos_network_guard --disable-warnings --tb=short .\functional_tests\test_plugin_discovery_identity.py .\functional_tests\test_orchestration_document_action_end_to_end.py .\functional_tests\test_orchestration_document_loader_reliability.py .\functional_tests\test_docs_app_surface_coverage.py .\functional_tests\test_docs_site_quality.py .\functional_tests\test_docs_release_notes_integrity.py

Earlier reviewed offline SDK gate: passed, 2,026 tests and 431 subtests.

python .\scripts\check_cosmos_response_boundaries.py --run-contracts

Manual packaged-runtime validation: passed, 101 existing cases, comprising the 38 real-loader/native HTTP/runtime cases and 63 real PDF/Word/PowerPoint/Excel extraction/evidence cases. The actual Linux image retained all 221 original production package versions; only four missing pinned test tools were installed in a disposable scratch user site. Fixtures were read-only, external networking was blocked, and all five raw implementation hashes matched the worktree. External model/storage I/O was isolated; this is not a live Azure canary.

Whitespace: passed.

git --no-pager diff --check
git --no-pager diff --cached --check

Live beta deployment and the six reported canaries remain unperformed pending separate authorization.

Documentation

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

Root cause, safe failure meanings, coverage limits, and rollout boundaries are documented in docs/explanation/fixes/ORCHESTRATION_PLUGIN_DISCOVERY_IDENTITY_FIX.md; the orchestration feature, Document Search, and logging references are updated.

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

Route/frontend items are N/A: no Flask routes, frontend settings plumbing, or browser assets changed. The reader identity and source-authority guards remain intact. Console archives, temporary build/tooling inputs, image artifacts, and local package-feed configuration are not committed.