Greptile Summary

This PR fixes a bug where queued chat messages were silently dropped when switching sessions by introducing chatQueueBySession — a per-session map that saves the active queue before a session switch and restores it on return. The overview's onSessionKeyChange handler is also unified with the existing switchChatSession helper to prevent a parallel code path with the same bug. The implementation is correct, and a focused unit test covers the round-trip save/restore behavior.

Confidence Score: 5/5

Safe to merge — the fix is well-scoped, correctly handles all switching scenarios, and is backed by new tests.

No P0 or P1 issues found. The save/restore logic is correct across all switching permutations (switch away, switch back, multiple round-trips, empty queue cleanup). Lit reactivity is properly handled via new object references. The unification of the overview switch path with switchChatSession is a deliberate, documented improvement.

No files require special attention.

_{Reviews (1): Last reviewed commit: "fix(ui): preserve queued chat messages a..." | Re-trigger Greptile}

Codex review: keeping this open for maintainer follow-up; there is still a little grit to resolve.

Keep this PR open. Current main still clears the Control UI chat queue on session switches, has no per-session queue store, and the supplied PR remains a focused implementation candidate for open bug #73621 rather than obsolete cleanup.

Best possible solution:

Review and either land or request changes on this PR as the focused client-side fix for #73621. The narrow boundary should be Control UI state: save the active queue before switching sessions, restore it when switching back, route all session-switch surfaces through one helper, and add the proposed regression test without changing gateway or disk persistence.

What I checked:

• Current main clears the shared queue in the common switch helper: resetChatStateForSessionSwitch() still assigns state.chatQueue = [] during every session switch, matching the PR's stated root cause rather than the proposed fixed behavior. (ui/src/ui/app-render.helpers.ts:87, b85edb3f0cf6)
• Overview session switching has a separate queue-clearing path: The overview onSessionKeyChange handler directly resets session chat state and clears state.chatQueue, so current main still has the parallel path the PR routes through switchChatSession(). (ui/src/ui/app-render.ts:1567, b85edb3f0cf6)
• No per-session queue state exists on main: AppViewState and OpenClawApp expose a single chatQueue; rg found no chatQueueBySession implementation in current UI source. (ui/src/ui/app-view-state.ts:110, b85edb3f0cf6)
• Queued follow-ups are active UI memory state until flushed: Queued messages are appended to host.chatQueue and later drained from that same in-memory array when connected and not busy; clearing it during navigation can drop an unsent follow-up. (ui/src/ui/app-chat.ts:165, b85edb3f0cf6)
• Docs describe the affected queued-follow-up UX: The Control UI docs state that normal follow-ups queue while a run is active, which is the user-visible behavior affected by this PR. Public docs: docs/web/control-ui.md. (docs/web/control-ui.md:172, b85edb3f0cf6)
• Existing test coverage does not assert restoration: The current switchChatSession test seeds chatQueue, but it does not assert save/restore behavior across switching back to the original session; the PR's proposed regression test remains useful. (ui/src/ui/app-render.helpers.node.test.ts:496, b85edb3f0cf6)

Likely related people:

• Ayaan Zaidi: Current-main blame and git log -S/-G for resetChatStateForSessionSwitch, chatQueue, and the overview switch path point to the commit that introduced the checked-out Control UI files and queue behavior. (role: introduced current-main behavior / adjacent UI owner; confidence: medium; commits: d8c4d7c3c10f; files: ui/src/ui/app-render.helpers.ts, ui/src/ui/app-render.ts, ui/src/ui/app-chat.ts)
• BunsDev: The PR timeline shows BunsDev was mentioned by the contributor and assigned for follow-up, though I did not find current-main code provenance for this exact UI path under that handle. (role: assigned maintainer / likely reviewer; confidence: low; files: ui/src/ui/app-render.helpers.ts, ui/src/ui/app-render.ts)

Remaining risk / open question:

• The proposed per-session queue store should get maintainer review for lifecycle details: restored queue ordering, inactive-session removal, and attachment payload retention while queued items sit outside the active chatQueue.
• Open PR fix(webchat): persist chat queue to localStorage with drain-on-reconnect #73154 overlaps in the broader browser-refresh/localStorage queue-persistence area, so landing should keep this PR's in-memory session-switch fix compatible with any later durable queue design.

Codex review notes: model gpt-5.5, reasoning high; reviewed against b85edb3f0cf6.

@BunsDev
I passed ai checks. CI failures are not related with my changes.
Please review my PR.