Bug

After a model call completes in the webchat dashboard, the agent-chat__run-status-label briefly shows "Done", then flips back to "In progress" and stays there permanently until page refresh.

Root Cause

Race condition between the terminal chat event and the sessions.list / sessions.changed response timing:

1. Agent run ends → chat "final" event arrives → UI sets chatRunStatus = { phase: "done" }, clears chatRunId → shows "Done" ✓
2. loadSessions is triggered (refresh after chat) → sends sessions.list RPC to gateway
3. Gateway responds with status: "running" because its session store hasn't been updated yet (async write)
4. loadSessions replaces sessionsResult → current session row gets status: "running" (overwriting the locally-reconciled "done")
5. 5-second toast timer fires → chatRunStatus = null
6. Now: isSessionRunActive({status: "running"}) = true → canAbort = true, hasTerminalRunStatus(null) = false → showAbortableUi = true → "In progress" displayed permanently

The same race applies to sessions.changed events that arrive after the terminal chat event with stale status: "running".

Key insight from debugging

[DEBUG hasAbortableSessionRun] true via session row: {
  key: 'agent:main:dashboard:...',
  status: 'running',    ← stale from server
  hasActiveRun: false   ← correctly cleared
}

isSessionRunActive checks status first (line 9-10 of session-run-state.ts): if status === "running" it returns true regardless of hasActiveRun.

Minimal Fix

In ui/src/ui/controllers/sessions.ts, after loadSessions response and in the sessions.changed event handler, if chatRunId is already null (local run ended), force-correct stale server values:

// After loadSessions replaces sessionsResult (~line 691):
if (!state.chatRunId && hasCurrentChatSession(state)) {
  const currentRow = state.sessionsResult.sessions.find(
    (row) => row.key === state.sessionKey,
  );
  if (currentRow && (currentRow.hasActiveRun === true || currentRow.status === "running")) {
    state.sessionsResult = {
      ...state.sessionsResult,
      sessions: state.sessionsResult.sessions.map((row) =>
        row.key === state.sessionKey
          ? { ...row, hasActiveRun: false, status: row.status === "running" ? "done" : row.status }
          : row,
      ),
    };
  }
}

// In applySessionsChangedEvent, after the field-copy loop (~line 457):
if (
  !state.chatRunId &&
  hasCurrentChatSession(state) &&
  nextRow.key === state.sessionKey
) {
  if (nextRow.hasActiveRun === true) {
    nextRow.hasActiveRun = false;
  }
  if (nextRow.status === "running") {
    nextRow.status = "done";
  }
}

Verified

• Reproduced on source-built gateway (2026.5.26, macOS, Node v25.8.1, model hy3-preview via tencent-tokenhub)
• Fix confirmed: after applying the above patch, status stays "Done" and does not flip back
• Debug log confirms the issue is status: "running" from server, not hasActiveRun

Affected files

• ui/src/ui/controllers/sessions.ts (both loadSessions and applySessionsChangedEvent paths)

Related context

• ui/src/ui/session-run-state.ts:9-10 — isSessionRunActive prioritizes status over hasActiveRun
• ui/src/ui/views/chat.ts:1069-1070 — showAbortableUi forces "in-progress" when canAbort && !hasTerminalRunStatus
• ui/src/ui/chat/run-lifecycle.ts:5 — 5-second toast timer (CHAT_RUN_STATUS_TOAST_DURATION_MS)