fix(browser): bound forced-close teardown to one deadline

[seonghobae]

Partial implementation of #28. This Draft now owns the ordinary and forced-close Agent Task teardown observers under one shared process-exit deadline while preserving exact root/set cleanup evidence.

Current exact parent and repair

Exact head 364912b7ff23b8ac88832d0f078e00d975707407, exact live base #146 812c0020bd2ecdb3eda39d999ed3327647550bdf. All prior #147 history remains ancestral, including the recovered parent synthesis, forced-close repair, ordinary-pass RED 3f483abb27eb8ae4abc6a2a7fe71d7632bc21e68, and ordinary production repair 9d07ca7b59553ad21c85b6efcb72c8154cb55c2f.

The ordinary pass previously performed _wait_for_linux_process_identity_exit and _wait_for_linux_process_identity_set_exit sequentially, allowing a surviving sampled descendant to consume two full PROCESS_EXIT_TIMEOUT_SECONDS windows. The production repair reuses the existing _wait_for_linux_process_teardown observer with one deadline. If a full sampled set was captured, root and set outcomes are preserved; if sampling failed before a full set was captured, the exact root identity is still observed while chromium_process_set_terminated remains unknown rather than fabricated.

Exact hosted CI on production-repair head 9d07ca7b... checked out that SHA and reproduced seven repository-contract failures. They were stale expectations for the replaced individual waiters, not new production failures: two static process-set assertions, three root-observer mock subcases, and two ordinary protocol-fault mock subcases. Production coverage on the same head succeeded and Manifest V3 Compatibility succeeded.

The current head reconciles only those inherited tests with the combined observer. The process-set contract now binds the full-set flag, fallback identity tuple, shared observer and conditional set evidence. Failure-path tests inject the shared observer and distinguish observed root exit/survival from observation errors without inventing set evidence. Protocol-fault regressions use the same combined observer for ordinary and forced-close lanes while retaining failure type, driver cleanup and diagnostic-redaction assertions. No timeout value, retry policy, workflow, dependency or production behavior changed after 9d07ca7b....

Current verification

• Hosted RED on predecessor 3f483abb...: CI 34038312988, Rust-contract job 101500347732, exact checkout, 229 tests with sole failure test_browser_pass_uses_only_the_combined_teardown_waiter; coverage succeeded.
• Hosted production-repair evidence on 9d07ca7b...: MV3 34043022052 succeeded; CI 34043022061 failed only at Python repository contracts with seven stale waiter expectations; production coverage job 101513049234 succeeded.
• Current exact-head CI 34046017203 is terminal success. Rust-contract job 101521080626 passed Python repository contracts, canonical formatting, workspace check, full tests, Clippy and API docs. Production coverage job 101521080749 is terminal success. Manifest V3 Compatibility 34046017253 is also terminal success.
• The ordinary double-budget review thread PRRT_kwDOTulPlM6coZwc is resolved only after that exact-head hosted GREEN.

Keep Draft. No counted approval, protected-main merge, release, cross-platform supervision, cgroup ownership, post-sampling descendant guarantee, or OS-wide orphan-absence claim is made.

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[devin-ai-integration]

Devin Review found 1 new potential issue.

[seonghobae]

Exact-head review after parent-first repair. Current #146 11944410450684809ee1a71a35c77abafc5358db is the merge base and the effective child delta remains the one shared-deadline teardown observer plus its two focused test paths. Fresh CI 33957022858 and MV3 33957022821 are queued, so no predecessor GREEN transfers and this is not approval. Keep Draft until exact-head hosted/browser/security evidence and dependency gates are current.

[seonghobae]

Current-parent adoption regression at exact #147 head 46e7585 (parent includes #146 812c002): ancestry alone does not preserve the valid parent delta. The child deletes all 169 lines / six tests in tests/test_agent_task_review_evidence_contract.py and reverses the parent pre-shutdown count range, ordinary cleanup-field forwarding, terminal HTTPException handling in browser/trial/aggregate boundaries, and obsolete HTTP-body recognizer removal.

Native discovery of that inherited filename collects zero tests (exit 5). Replaying the exact parent test module in memory against the current child runner, without writing files or launching a browser, executes six tests and reproduces 10 assertion failures plus 8 uncaught protocol-error cases. The preceding 222-test child snapshot does not cover these omitted regressions.

Required repair is non-lossy reconciliation: retain the combined forced-close observer and its deadline tests, restore the parent's review repairs and six tests, then adapt only the forced-close observer injection to the child's actual shared observer if needed. Do not remove tests, weaken the count/type gate, restore raw diagnostics, or treat base ancestry as successful delta inheritance. Source changes are not started here while the current writer route is being checked. This is a repair finding, not a Close condition or eligible approval.

Follow-up at exact #147 af1b98b: the synthesized parent runtime repairs and all six inherited methods are restored. Native focused discovery executes six methods; full native discovery executes 228. Both fail only the two forced-close BadStatusLine / IncompleteRead subcases at inherited line 108: the test patches _wait_for_linux_process_identity_exit, but production correctly calls _wait_for_linux_process_teardown. The unpatched reader remains live for both timeout budgets, which also makes the focused run take about 10 seconds. Preserve the ordinary-lane mock/assertion; inject the combined observer with (False, False) for forced-close and assert its (321, 654, ((321, 654),)) arguments. Keep all existing failed-denominator, cleanup, root-alive, driver-terminated and diagnostic-redaction assertions. This is a minimal test reconciliation, not a production timeout/retry change. No source write is active here on #147; #251 remains this task's sole writer lane.

Resolved test reconciliation at current #147 3dff28d: after the temporary route closed, exact source stayed unchanged and contacted tasks confirmed read-only ownership, this task took the isolated test-only lane. Fresh af1b98b RED reproduced both failures; the repair specifies each lane's actual observer/result/arguments and preserves every assertion and all six methods. All six focused and all 228 native tests now pass; compileall and complete Rust 1.97.1 gates pass. Numerical production coverage is 415/415 functions, 3555/3555 lines, 4444/4444 regions and 476/476 branches. Production and workflow blobs are unchanged. The pinned branch warning remains explicit, hosted checks need the new exact head, and the separate ordinary-pass deadline thread remains unresolved. This is a verified forward test repair, not approval, browser acceptance or protected-main delivery.

[seonghobae]

Exact-head review on af1b98ba377c73b88baa9633e2232e7f76e76f36: the parent-synthesis artifact was a real repair finding, not a reason to Close or rewrite history. Production already used _wait_for_linux_process_teardown, while the inherited process-termination contract still required the obsolete two-waiter sequence. Commit af1b98ba... restores only that child-owned shared-deadline assertion and retains #146's newer http.client.HTTPException evidence boundary. Fresh compare against exact parent 812c0020... is ahead-only with exactly three semantic paths. Current CI/MV3 runs are non-terminal, so this review records source consistency only, not hosted GREEN, approval, or merge readiness.

[seonghobae]

Ordinary teardown shared-deadline writer RELEASED — 2026-09-06 18:07 UTC

OriginWeave hourly writer releases the bounded #147 source/test/PR-state slice at unchanged exact head 364912b7ff23b8ac88832d0f078e00d975707407, exact live base #146 812c0020bd2ecdb3eda39d999ed3327647550bdf, Draft. All prior history remains ancestral, including RED 3f483abb27eb8ae4abc6a2a7fe71d7632bc21e68, ordinary production repair 9d07ca7b59553ad21c85b6efcb72c8154cb55c2f, and the test-only reconciliation descendants.

Fresh exact-head hosted proof is now terminal GREEN: CI 34046017203; Rust contracts job 101521080626 passed Python repository contracts, canonical formatting, workspace check, full tests, Clippy and API docs; Production coverage job 101521080749 succeeded; MV3 34046017253 succeeded. The sole remaining ordinary double-budget review thread PRRT_kwDOTulPlM6coZwc was resolved only after this exact-head proof. No self-approval, force update, workflow/ruleset/secret mutation, protected merge, tag or release occurred.

Preserved acquisition and repair history

This lease was originally acquired for the ordinary Agent Task teardown double-budget finding. The hosted RED 3f483abb... demonstrated that the non-forced-close pass still used two sequential root/set waiters. Intervening normal descendant 9d07ca7b... replaced them with the existing _wait_for_linux_process_teardown shared observer. Exact hosted execution on that production head exposed seven stale repository-test expectations while coverage and MV3 succeeded; later test-only descendants reconciled only those expectations, preserving root/set evidence semantics and leaving production behavior unchanged after 9d07ca7b....

The invalid overlapping later claim recorded in comment 5560259746 was explicitly released and its valid production descendant was adopted without history rewrite.

[seonghobae]

Ordinary teardown shared-deadline writer RELEASED — overlap correction

Fresh coordination re-read found an earlier unreleased lease in comment 5559729227 (2026-09-06 14:04 UTC) owning this exact #147 ordinary-pass shared-deadline slice. My later acquisition was invalid and is explicitly released now; no further #147 source/docs/PR-state mutation will be made by this task until that earlier writer releases.

Before detecting the overlap, normal publication advanced the branch from the earlier writer's RED 3f483abb27eb8ae4abc6a2a7fe71d7632bc21e68 to 9d07ca7b59553ad21c85b6efcb72c8154cb55c2f. The intervening delta is one ordinary descendant commit, modifying only scripts/ci/run_mv3_compatibility.py (+14/-7): it replaces the ordinary pass's two sequential process-exit waiters with the already-existing _wait_for_linux_process_teardown pattern, preserves the captured-set fallback/root singleton and keeps chromium_process_set_terminated=None when no full set was captured. The prior RED/test commit and all earlier history remain ancestors; no force update, test deletion, workflow/ruleset change, merge, tag or release occurred.

Exact hosted RED on predecessor 3f483... is real: CI 34038312988, Rust-contract job 101500347732, checkout exact 3f483..., 229 Python tests with the sole failure test_browser_pass_uses_only_the_combined_teardown_waiter; coverage job 101500347669 succeeded. This new 9d07ca7b... descendant has not yet been accepted as GREEN here. The earlier writer should refetch 9d07ca7b..., inspect/adopt or amend this non-force descendant as appropriate, run exact-head verification, resolve the thread only after proof, and explicitly release its original lease. This task retains no #147 writer.