fix: allow deleting remote sessions the host no longer has

[damienrj]

Deleting a disconnected remote session (the "This session is no longer available" state) failed with Session not found: <id> and the row came right back.

Deleting a chat archives it on the backend. When the remote host has already lost the session, the archive call rejects with Goose's session-not-found error. The store then rolled back the optimistic archivedAt, leaving a sidebar row that could never be deleted.

Now chatSessionStore.archiveSession checks for that case. If a remote session's archive fails with isAcpSessionNotFoundError, the store removes the session locally along with its remote session record, and AppShell's archive flow finishes normally. Any other archive failure still rolls back and shows the error.

Only an explicit user archive (the sidebar action) forgets the dropped session. Auto-archive and berdctl session archive leave it in place, so its cached history stays visible instead of being deleted in the background.

Before — deleting the unavailable remote chat fails and the row stays:

🤖 Generated with Claude Code

[morgmart]

🤖 Automated code review

REQUEST_CHANGES: The remote-session cleanup fixes the undeletable row, but removing the session inside the store clears active-session state before AppShell decides whether to navigate home. Supplied GitHub evidence shows the reported checks completed successfully; required checks still govern merge readiness.

Deterministic publication result: 1 blocking and 0 non-blocking inline finding(s) publishable; 0 duplicate(s) suppressed; 0 blocking screenshot-evidence requirement(s) in this review body.

[morgmart]

🤖 Automated code review

REQUEST_CHANGES: the active-session navigation fix can overwrite newer navigation when the remote archive resolves late. The changed AppShell navigation flow also lacks screenshots or a short screen recording. The supplied GitHub check evidence is structurally valid and all captured checks completed successfully; required checks still independently govern merge readiness.

Deterministic publication result: 1 blocking and 0 non-blocking inline finding(s) publishable; 0 duplicate(s) suppressed; 1 blocking screenshot-evidence requirement(s) in this review body.

🤖 Blocking · Screenshots needed

This PR changes Berd’s graphical interface. Please add screenshots or a short screen recording so the visual result can be reviewed. Screenshots are review evidence; they do not replace accessibility, responsive, theme, localization, or behavior validation.

[damienrj]

[damienrj]

The chat is gone after picking archive.

[morgmart]

🤖 Automated code review

COMMENT: the full exact PR comparison has no new publishable findings, but Atlas identified a product-contract decision about presenting permanent local removal through the existing Archive action. One proposed navigation-race finding is suppressed because it is the same underlying issue as a resolved automation thread with a substantive human reply. Supplied GitHub check evidence is structurally valid and all captured checks completed successfully; required checks still independently govern merge readiness.

Deterministic publication result: 0 blocking and 0 non-blocking inline finding(s) publishable; 1 duplicate(s) suppressed; 0 blocking screenshot-evidence requirement(s) in this review body.

[morgmart]

🤖 Automated code review

REQUEST_CHANGES: an older missing-session archive response can still remove a session after a newer unarchive operation has won. The previously reported late-navigation issue is suppressed under its protected resolved thread. Supplied GitHub check evidence is structurally valid and all captured checks completed successfully; required checks still independently govern merge readiness.

Deterministic publication result: 1 blocking and 0 non-blocking inline finding(s) publishable; 1 duplicate(s) suppressed; 0 blocking screenshot-evidence requirement(s) in this review body.

[morgmart]

🤖 Automated code review

APPROVE: the full exact PR comparison has no new publishable findings or escalations. The only current engineering concern is the same underlying late-navigation issue as a protected resolved thread with a substantive human reply, so it is suppressed. Supplied GitHub check evidence is structurally valid and all captured checks completed successfully; required checks still independently govern merge readiness.

Deterministic publication result: 0 blocking and 0 non-blocking inline finding(s) publishable; 1 duplicate(s) suppressed; 0 blocking screenshot-evidence requirement(s) in this review body.

Pending checks: 1 check(s) are not complete.

This approval reflects the completed code review only; merge readiness remains governed by the repository's required checks.