perf(ci): isolate launcher evidence from frontend qualification

[Chris0Jeky]

Stack / scope

Depends on #2865. Parent-first merging and exact-head requalification are required. R4: park for maintainer and independent fresh-context review under SC-10; no auto-merge.

Move the existing Linux source-launcher step to an independent source-launcher child inside reusable-frontend-unit.yml. Its exact command, Linux guard and ten-minute step timeout remain. The new job has a fifteen-minute wrapper budget and a credential-free checkout. Existing Linux/Windows frontend job names, matrices, lint/typecheck/build/PWA/coverage/bundle checks and failure-only artifacts are retained.

The source-launcher and frontend jobs run independently. A launcher failure still fails the reusable call/E2E prerequisite, but does not prevent collection of unrelated frontend evidence. This adds a small job setup cost; no measured speedup is asserted.

Canonical accounting

Add source-launcher-linux to the existing shadow policy and one conservative backend/frontend/scripts input group. Existing policy content is unchanged apart from those two additions; the original blob was reproduced as 8fc840fac37bef19790e3b4ec6e03280ea5c81ee and parsed-policy subtraction was verified. No schema version replacement, enforcement flip or required-context registration.

The Taskdeck adapter uses the split closure only when the canonical policy contains the new lane. Historical policies keep the broad mixed-job contract; no retroactive reinterpretation of old results. Every Taskdeck contract remains unreviewed/reuse-disabled.

Tests / evidence

Combined node --test scripts/ci/smart-ci/continuation.test.mjs scripts/ci/smart-ci/launcher-suite-placement.test.mjs: 264 passed, 0 failed/skipped/cancelled, local Node 22.16.0/Linux. Includes updated launcher-placement contracts (exact command/timeout, one Linux invocation, full OS matrix, unconditional semantic checks, read-only new job and canonical lane) plus current and legacy input-boundary tests. Reusable YAML syntax parsed locally.

The real launcher/product frontend suites and the full pre-existing Smart CI suite were not run locally. Exact-head hosted configured-Node/full required CI and independent review remain owed. Fixture success is not product qualification.

Coordination / docs / rollback

Lease: #2332 comment 5610751439. #2858 launcher code/tests and #2838/#2840 hardening implementations are not edited; preserve their checkout additions during integration. Canonical coordinator-owned docs/settings are untouched. docs/ci/continuation/LANES.md documents the new boundary, historical compatibility, rollout and coordinated rollback.

Rollback the job move, lane/path group and adapter contract together. Never delete the new launcher job without restoring the original suite.

Refs #2331, #2332, #2329.

[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-10T02:48:43.142189Z	c959c83	New commits

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: e66711b3bd

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[Chris0Jeky]

Hosted correction at 3f52e9ba226ce5040535b2a1b2f03ad7c7916369 (non-forced update, parent #2865 correction included): the first hosted self-test had 409 pass / 9 fail. Eight failures came from the new catch-all path group (unmapped nightly group and changed overlap), and one from the inherited E2E no-frontend assertion. The new group has been removed, not merely exempted: the launcher lane is added to fifteen EXISTING ownership groups, preserving all group IDs, patterns and risk classes. Removing lane/references reconstructs the original parsed policy exactly. This also avoids masking previously unknown paths. The parent's E2E assertion now checks the intended barrier and retains independent runtime-setup assertions. Earlier failure is retained; fresh exact-head hosted checks are pending. No merge/settings action.

[Chris0Jeky]

Independent review and single fix-round checkpoint

Reviewed this slice with an independent Terra reader, then reviewed only the blocking fix diff. Current head: c959c83. The integrated final tree is byte-identical to independently reviewed 636a17329e5a480d702fcf1a9585cf279bbf60fb after preserving each original stack branch and propagating fixes with merge commits.

Blocking changes: prohibit Git lazy fetch/protocol execution in immutable readers; use independently trusted self-contained export verification; repair Windows CRLF and privilege-free symlink fixtures. Slice-specific changes remain visible in this PR diff. No result-reuse activation or settings changes.

Validation: cumulative Windows control command node --test scripts/ci/smart-ci/*.test.mjs passed 509/509, no failures/skips/cancellations. Independent fix checks: core/repository 110/110; export/workflow 11/11. node scripts/check-doc-links.mjs passed, 683 Markdown files and zero broken relative links. These are additive; hosted CI at the current head/base is still required.

Nonblocking findings are tracked once on #2336: #2336 (comment) . Review budget: one original pass and one scoped fix verification, complete. Original E2E/nightly-map findings were already corrected in the previous authored heads and remain covered by the green control tests.

The maintainer's current local request explicitly includes finishing and merging this CI work. Parent-first merge order remains #2863, #2864, #2865, #2867, #2868, #2869, #2871; children are retargeted only after parents land, with moved-base requalification. No branch deletion while it is a stack base.

[chatgpt-codex-connector]

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Reviewed commit: c959c83036

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[Chris0Jeky]

Parent #2865 merged as 688e4a0 at 04:26:59 UTC after exact-head required CI run 34434822721 succeeded, with no pending/failed checks or unresolved review threads.

This PR now targets main, confirmed through the API. Updating the branch refreshed its head to 97a0dde. A complete tree comparison against reviewed head c959c83 found no source changes. The code review remains applicable; fresh full hosted qualification is running before merge.