Implemented in commit 1979a25ef and deployed to server A as 1979a25-20260917063441; service health and frontend HTTP checks passed. User live chat acceptance remains pending. This supersedes the failure status in the two earlier architecture/isolation reviews; it does not claim production verification.

Selected UI state, provider delivery, canonical history, and native recovery had independent lifetimes. Delayed operations could follow the selected tab, stale snapshots could overwrite newer history, and a delivery response could precede durable acceptance. The fixes enforce identity and persistence boundaries without requiring a UI rewrite.

• Tabs and ownership: submissions capture account generation, tab, session and submission identity. Builder submissions bind to their exact created conversation. Workflow options and selected servers come from the source tab/preset, including background queue delivery. Established Work continuation fails visibly when its requested session cannot be verified instead of substituting another conversation.
• Account transitions: persisted tabs, drafts and queues are namespaced by workspace and owner; login, OAuth, refresh, logout and cross-window account changes invalidate stale callbacks. Legacy migration requires verified identity. Requests capture their authorization synchronously and late old-token failures cannot clear the current account.
• Input: store-owned composer revisions protect drafts across remounts and delayed success/failure. Attachment upload and acceptance cannot overwrite newer drafts. Submitted file context is consumed after acceptance while preserving newly added files.
• Queues: an account-scoped controller processes every eligible tab independently of selection. Manual steering and background execution share a delivery lock and stable receipt. Rejection retains messages and exposes retry; accepted delivery consumes only the exact captured queue occurrence/prefix. Runtime processing locks do not survive reload as permanently busy state.
• History: account/session generation and monotonic snapshot revisions reject stale hydration. Backend history writers share per-path locks, reread canonical state and merge existing content. Canonical snapshots receive incrementing revisions; opaque metadata and structured entries are retained.
• Acceptance: interactive query/live-input dispatch first persists an owner/project/session-scoped submission journal. Idempotent retry reuses the receipt; uncertain delivery returns an explicit conflict and is never automatically resent through another endpoint. An owner-scoped receipt endpoint supports status recovery. Acceptance does not claim provider completion.
• CLI recovery: new demand is retained while reconciliation runs; missing history can retry. Durable owner-scoped markers survive process restart. A cancellable scanner retries unresolved native flushes every 30 seconds using four workers. Unknown ownership fails closed. Recovery does not resend messages or guess that text matching proves delivery.
• Observers: unmounting one ChatArea no longer disconnects every session. Delayed polling, stop/new-chat and response callbacks check their original account/session before changing state.
• Schedule/webhook tabs: automatic run discovery no longer adds these read-only runs as chat tabs. Explicit run access remains available. The separate agent's notification feature changes and other unrelated working-tree changes were preserved.

• TypeScript project build check: npx tsc -b passed.
• Latest combined frontend run: 147 tests across 15 files passed, covering authentication transitions, hydration/session isolation, restoration, composer ownership, queues/manual steering, Builder targeting, promise-lane aliases, workflow discovery and source settings helpers.
• Combined Go server tests passed for product conversation identity, profiles, history, native recovery, concurrent snapshot writers, submission journaling, live input, session ownership and existing auto-notification ownership. A broader backend access/resume/ownership suite also passed.
• git diff --check passed.
• Historical queue extraction reproducer now points to the replacement controller regression suite when the removed vulnerable effect is absent.

Local logs: /tmp/chat-reliability-final-tests.log, /tmp/chat-reliability-tsc.log, /tmp/chat-backend-combined-tests.log, /tmp/chat-backend-review-tests.log.

The transcript mutex protects one active backend process. Concurrent writing replicas still require storage-level compare-and-swap or a transactional conversation store. The configured AgentWorks state root must persist across replacement/deployment for recovery markers; acceptance journals are stored in the durable workspace under each user’s chat_history/submissions directory.

Native adapters still lack application turn IDs. Ordered text-occurrence import remains a repair heuristic; ambiguous provider execution cannot be called exactly-once. Unresolved markers are retained and periodically retried, without automatic garbage collection. These changes are incremental safeguards, not a replacement transactional conversation database.

Deployment completed on 2026-09-17. No live provider/browser restart acceptance matrix was performed. Before production sign-off, validate two users with multiple tabs, queued input while another tab is selected, delayed native flush, reload/restart during acceptance and completion, and a context-dependent follow-up through each supported CLI. Verify both visible history and actual provider context; unit checks alone cannot establish that result.