feat(btw): deliver background results to the originating request

[YUZHEthefool]

Summary

Wire detached work to response decoration and delivery without ending the originating WebChat request at acknowledgement. Keep per-request output/statistics identity and release events/files on completion, failure, or cancellation.

Related issue

Related: #126
Parent: #122
Design: #28

Stack

• Base: split/btw-work-runtime. Depends on PR #137.
• Follow-up PRs: #139.

Behavior

Deliver background results through the existing response decoration and sending stages, preserving the originating request identity. Release temporary files and event registrations after completion, failure, or cancellation.

Non-goals

A new HTTP protocol, a session-wide busy flag, or a separate response pipeline is not required.

Implementation notes

Base branch: split/btw-work-runtime. Depends on PR #137. This PR shows only this feature's changes relative to that dependency. The original prototype at 33ee103a62937db3e930c89ba47a648b75cc7772 is provenance; integration follows current master's owners and authorization contracts. The parent issue records review/integration order.

No new HTTP contract or dependency changes. Feature settings and behavior are documented in both languages.

Validation

91 focused delivery, work, scheduler, lifecycle and internal-agent tests passed initially. After integrating B1 metadata and narrowing the scheduler cleanup awaitable, 70 related tests passed; the complete CI quality Pyright project passed with the Linux platform model.

Python checks used the existing Python 3.14.1 environment with python -m pytest and task-local --basetemp directories. Local Node was 24.11.1; CI must validate the pinned toolchain. Relevant scoped formatting and Markdown checks were run. The root tracker records the final combined validation. No live model evaluation is implied by deterministic tests or documentation checks.

Compatibility and risk

Depends on B3. Real scheduler plus WebChat emitter/queue tests cover concurrent request IDs, cancellation before startup, delivery failure, and closed-loop admission. Profile work closes before transport/runtime dependencies. No real provider or live IM was used.

Checklist

• A corresponding development Issue exists and this PR contains one feature or experiment.
• Tests and bilingual documentation accompany the change, or missing experimental implementation is explicitly described.
• Existing authorization, current APIs/configuration, Python 3.14+, and integrated documentation constraints are retained.
• No dependencies, credentials, generated site output, or fork publication claims are introduced.
• A human maintainer review and separate AI-assisted review have approved merging.

Repository references: AGENTS.md, GOVERNANCE.md, AI_POLICY.md, and the feat PR template.

Agent note

Codex prepared this PR at the user's request to split the original #28 implementation into reviewable features, with only classifier experiments marked as drafts. AI assisted extraction, current-path adaptation, tests, and English descriptions. The validation above was performed locally; remaining limitations are stated explicitly. This note is not a maintainer approval. No PR has been merged.

[xero-team-bot]

⚠️ This PR conflicts with its base branch and needs a rebase.

git fetch origin split/btw-work-runtime
git rebase origin/split/btw-work-runtime
# after resolving the conflicts
git push --force-with-lease

The needs-rebase label is removed automatically once the conflicts are gone.
(Xero-Team/AstrBot · detected by xero-bot)

[xero-team-bot]

✅ Conflicts resolved; removing the needs-rebase label.