[brennanb2025]

	Files	Added	Deleted	Net
Test	16	$\color{#1a7f37}{\Huge{\mathbf{+}}}$​1784	$\color{#cf222e}{\Huge{\mathbf{−}}}$​86	$\color{#1a7f37}{\Huge{\mathbf{+}}}$​1698
Prod	32	$\color{#1a7f37}{\Huge{\mathbf{+}}}$​723	$\color{#cf222e}{\Huge{\mathbf{−}}}$​181	$\color{#1a7f37}{\Huge{\mathbf{+}}}$​542

ELI5

After an agent dies, its chat can stay stuck on “Working” or an old approval. If saving the result fails, starting the next owner clears the only saved proof of which agent generation died. A restart can then lose the information needed to finish that old work.

This PR changes nothing users see yet. It keeps the proof after the next owner starts. The next PR in this stack will use it to finish old work when ownership changes, fail a start if that result cannot be saved, and retry at the next ownership attempt. Opening history will stay read-only.

What Changed

The execution host now stores one immutable closed-owner fact per session and owner generation in its existing chat database. Each positive exit, proven eviction, failed acquisition with proof, or proven replacement commits the fact with its ownership transition, before mutable evidence is cleared. Facts contain the proof, the old process identity without its spawn token, and the known journal cutoff. They survive replacement and restart.

The store exposes facts oldest first and passes the committed fact to death listeners while preserving current callers' notification behavior. A journal receipt can delete a fact in the same transaction that saves the result making it unnecessary; deleting the session also deletes its facts. This PR does not invoke that receipt from production. Host-only process snapshots and existing fence comparisons reject stale probes without closing a successor; public wire shapes are unchanged.

The host schema advances to version 5 so an older host uses the existing read-only refusal instead of changing owners without maintaining this history. A one-time migration preserves safely attributable old proof; missing identities and historical cutoffs stay unknown.

Why

Keeping the single mutable field loses old proof when the next owner starts. An in-memory copy cannot survive restart and misses replacement's fresh probe. A “cleanup owed” flag would duplicate state without recording which owner actually died. A past ownership fact preserves the cause and generation, and its delete receipt provides a definite end when the journal result commits.

Compared with the common pattern:

• INTENDED: closure requires positive execution proof because agents can outlive the app and run over SSH. A disconnect or unverified owner remains unverifiable.
• TEMPORARY: settlement stays at its current placement. The next PR in this stack moves it to ownership changes, uses these facts, and retires them with the resulting journal transaction.

Linked Issue

Maintainer work in the approved lane C stack. No separate issue is linked. This is preparation for the stuck-chat fix, not a claim that this PR alone fixes it.

Visual Proof

N/A — this PR changes host-only ownership persistence and preserves existing UI and ordinary interaction behavior.

Testing

• I manually tested these changes locally
• Automated tests added/updated

On macOS, the final explicit-file run passed 42 files and 434 tests with two workers and background launch enabled. New real SQLite tests cover positive ownership transitions and rollback, fresh reservation proof, retention after replacement/restart, no proof on expiry/uncertainty/unproven release, stale fence and same-fence identity protection, receipt commit/rollback, record deletion, migration and newer-schema write refusal. Existing ownership, restart, attachment, journal and stored-record tests passed unchanged apart from the state fixture's new history map.

Oxfmt, changed-file oxlint, and the changed-code quality gate pass. React Doctor reports four existing warnings in dependency-stack files and no new findings. Node, web and cli typechecks pass. No build, live SSH/WSL run or rendered UI check is claimed here; CI covers the full suite. Remote and folder scopes are covered by fixtures.

AI Disclosure

Review

Second PR of a stacked series. The branch also contains #26555 and #26577 (merged in, unchanged) because the follow-up builds on them; their diffs are reviewed in those PRs.

Agent skill upstream boundary

• Not applicable, or this change copies or mechanically translates no upstream skill-installer source, tests, fixtures, registry entries, path tables, comments, or documentation.

Notes

Merge #26555 and #26577 first, then #26664, then this PR. Host schema fencing preserves older-host safety; clients exchange the existing wire shapes. The execution host owns proof and history, including remote and WSL scopes. Folder workspaces require no Git operation. Facts contain no account home, claim key, or spawn token. No retry flag or timer is introduced.

Author: Brennan Benson (@BrennanKB5).

Checklist

• This PR is small and focused
• I explained what changed and why (ELI5, the user-facing before/after, the mechanism, and why over the alternatives)
• Before/after screenshots or videos attached for UI changes, or N/A with reason
• Self-reviewed for correctness, security, and performance
• Cross-platform, SSH/remote, and path/shortcut impact considered (or N/A)
• pnpm lint, pnpm typecheck, pnpm test, and pnpm build pass (or CI will cover; local preferred)

[brennanb2025]

Closing as superseded by #26867.

This PR kept the proof that an agent is gone after the next owner starts, so that leftover work could be cleaned up later. #26867 removes the need for that proof. Leftover work is now settled when ownership changes:

• each saved row records which agent run wrote it;
• the app works out "what is still running" from that;
• one background retry finishes any cleanup that couldn't be saved straight away.