feat(hooks): include final assistant message in Stop payload

[ousamabenyounes]

Related Issue

Resolve #2123

Problem

Stop hooks cannot inspect the assistant response that is about to end the turn, so they cannot validate or conditionally reject that response.

What changed

• include the last assistant message's text in Stop hook input as last_assistant_message
• preserve the exact concatenated text while excluding non-text content
• cover the real hook subprocess/JSON boundary with an integration test
• document the field in the English and Chinese hook references
• add a patch changeset

Test verification (RED → GREEN)

RED on unmodified upstream origin/main (17dfd4976) with only the regression test:

AssertionError: expected history to contain the final assistant text
Actual Stop continuation reason: "Blocked by Stop hook"

GREEN with this patch:

Test Files  1 passed (1)
Tests       1 passed | 82 skipped (83)

Full local suite proof

The complete agent-core suite is iso-or-better against an exact clean-main baseline:

clean main: 4053 passed, 63 failed, 3 expected failures, 30 skipped, 1 todo
patched:    4054 passed, 63 failed, 3 expected failures, 30 skipped, 1 todo

The same 63 pre-existing failures occur in both runs and come from missing local workspace/profile fixtures (workspace.additional_dir and the reviewer profile); this patch adds one passing test and no failure or skip.

Additional validation:

pnpm --filter agent-core typecheck
pnpm --filter agent-core build
pnpm exec oxlint --type-aware <changed TypeScript files>  # 0 errors
pnpm exec sherif
pnpm exec changeset status
pnpm --filter kimi-code-docs build
git diff --check

Independent PR review: PASS. Final read-only Codex review: PASS.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

Follow-up review fix

The v2 agent path now sends the same last_assistant_message field as the legacy Stop-hook path, sourced from the latest assistant entry in v2 context memory. The generated v2 state manifest was refreshed after the import change.

• RED: the v2 integration test received { stopHookActive: false } without the documented assistant field.
• GREEN: v2 external-hook + manifest tests pass 22/22; the full repository run reached 16,852 passing tests with one unrelated Kap Server timeout that passed immediately in focused replay.
• Typecheck, lint (0 errors), Sherif, changeset, docs build, independent review, OCR/Codex review, and explicit revert proof pass.

[changeset-bot]

🦋 Changeset detected

Latest commit: ee99610

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[chatgpt-codex-connector]

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[ousamabenyounes]

Addressed the v2 Stop-hook payload gap in ee99610ba: last_assistant_message is now populated from the latest v2 assistant context, matching the documented legacy contract. RED reproduced the missing field; GREEN: v2 hook/manifest tests 22/22, full suite 16,852 passed with one unrelated Kap timeout green on focused retry. Typecheck, lint, Sherif, changeset, docs, independent review, OCR/Codex, and revert proof pass.