fix(process): verify Windows PTY descendant cleanup

[akivavh]

Summary

• snapshot the complete Windows PTY-owned PID/start-time tree before PTY teardown can erase parentage
• terminate only the attributable tree with the existing Windows tree-kill primitive and verify every captured identity is gone before reporting killed
• fail closed on identity mismatch, timeout, nonzero taskkill, or surviving descendants while preserving idempotent cleanup and existing browser cleanup callers

Verification

• focused Windows process-registry regression: 10 passed
• existing browser orphan-reaper and cleanup callers: 17 passed
• canonical targeted process-registry run: 43 passed (four exact pre-existing Windows-red tests excluded and reproduced against the base)
• native provider-free Windows probe: six attributable identities terminated; unrelated sentinel preserved during kill; repeated kill returned already_exited; simulated taskkill failure returned an error without PTY teardown
• Ruff: pass
• git diff --check: pass
• Windows footgun classifier: zero findings on lines added by this change

Scope and limits

This PR repairs Hermes core PTY ownership and cleanup semantics. It does not use global image-name termination, add Job Objects, modify provider behavior, or claim live Claude/Remote Control certification. The unfiltered repository suite and remote CI remain to be evaluated by this PR.

[teknium1]

Thanks for the focused Windows PTY cleanup work. I found no blocking issue in this sweep.

• Current main directly terminates PTYs at tools/process_registry.py:1607-1613; it does not verify the Windows descendant tree.
• This change snapshots and verifies identities in tools/process_registry.py:548-606, makes taskkill failures explicit at tools/process_registry.py:665-696, and delays PTY-handle teardown until verified cleanup at tools/process_registry.py:1693-1741.
• The PR base cc4cab2f592e60a197e796506de9168f74baf3ea is the current main, so this is directly salvageable without rebase work.

Automated hermes-sweeper review.

[GottZ]

This was generated by AI during triage.

Summary

Five PRs are associated with this complex, but only #75113 addresses the reported Windows PTY descendant-cleanup failure: it captures attributable process identities before PTY teardown, terminates that tree, and verifies cleanup. The four closed, retracted PRs modify unrelated governance, image-ingest, or Discord behavior and do not address the process-registry cause.

Related pull requests

• #25160 [closed] related — (+611/-0) — unrelated, retracted: This added an opt-in GitHub governance preflight around mutating tools, not Windows PTY ownership or descendant cleanup; although closed, it remains relevant here only to establish that it is not a competing fix.
• #26104 [closed] related — (+278/-0) — unrelated, retracted: This reported successful image generation to an agent-ops ingest endpoint and did not touch process cleanup; although closed, it remains relevant only as an out-of-scope association.
• #37676 [closed] related — (+185/-3) — unrelated, retracted: This converted Discord Markdown tables into aligned fenced text and has no overlap with the Windows PTY failure; although closed, it remains relevant only to exclude it from consolidation.
• #37696 [closed] related — (+117/-3) — unrelated, retracted: This routed Discord streaming edits through thread metadata rather than the parent channel, without changing process ownership or termination; although closed, it remains relevant only to confirm that it is not a duplicate.
• #75113 related — (+399/-21) — keep open with a salvage path: The diff directly addresses the cause by snapshotting the Windows PTY-owned PID/start-time tree before parentage is lost, making taskkill failures explicit, and withholding PTY teardown until captured identities are verified gone. This agrees with the keep_open maintainer-bot review, which identifies the salvageable core at tools/process_registry.py:548-606, tools/process_registry.py:665-696, and tools/process_registry.py:1693-1741 against current main behavior at tools/process_registry.py:1607-1613.

Suggested consolidation

Keep #75113 open with the concrete salvage path of retaining its attributable PID/start-time snapshot, explicit taskkill error handling, survivor verification, and delayed PTY-handle teardown. The maintainer-bot verdict reports no blocking issue and a current-main base, while #25160, #26104, #37676, and #37696 are already closed, retracted, and technically unrelated rather than duplicates; no merge recommendation is supported by the recorded lane evidence.

Cross-PR triage: Reviewed 5 pull requests and 0 issues in this complex. Diffs were read for 4 of 5 PRs (rest unavailable); Assessment working set: 50 kB of PR diffs, 1 kB of issue/PR text, 0 verify verdicts. verdicts reflect diff content, not PR titles. Part of an automated triage batch.