fix(tab-bar): offer Resume in New Native Chat only while the tab's agent is running (#27520)

The terminal tab menu found its conversation through the tab-title lookup, which also
falls back to retained and sleeping records an exited agent leaves behind. Pass a
running-agents-only option for the move; tab titles keep the remembered conversation.

src/renderer/src/components/tab-bar/tab-session-history-switch.test.ts

@@ -3,6 +3,7 @@ import { useAppStore } from '@/store'
 import type { AppState } from '@/store/types'
 import { makeRepo, makeTerminalTab, makeWorktree } from '../worktree-jump-palette-test-fixtures'
 import { makeAgentStatusEntry } from '@/runtime/sync-runtime-graph-test-harness'
+import { collectAiVaultTitleRequests } from '@/lib/ai-vault-tab-title-requests'
 import type { AiVaultListArgs, AiVaultSession } from '../../../../shared/ai-vault-types'
 import {
   claimAiVaultForcedRescan,
@@ -152,6 +153,103 @@ describe('resolveTabSessionHistorySubject', () => {
     ).toEqual(cliSubject)
   })
 
+  it('finds an agent a restart reattached to before it reports again', () => {
+    const [[paneKey, entry]] = Object.entries(liveClaudeEntry)
+    expect(
+      resolveTabSessionHistorySubject(
+        makeState({ [paneKey]: { ...entry, restoredUnconfirmed: true } }),
+        { tab: { id: 'term-1', worktreeId: WORKTREE_ID } }
+      )
+    ).toEqual(cliSubject)
+  })
+
+  // What Orca remembers once the agent exits and the pane is back at its shell prompt.
+  const exitedAgentRecords: Record<string, Partial<AppState>> = {
+    retained: {
+      retainedAgentsByPaneKey: {
+        'term-1:leaf-1': {
+          entry: liveClaudeEntry['term-1:leaf-1'],
+          worktreeId: WORKTREE_ID,
+          tab: makeTerminalTab('term-1', WORKTREE_ID, 'claude'),
+          agentType: 'claude',
+          startedAt: 1
+        }
+      }
+    },
+    sleeping: {
+      sleepingAgentSessionsByPaneKey: {
+        'term-1:leaf-1': {
+          paneKey: 'term-1:leaf-1',
+          tabId: 'term-1',
+          worktreeId: WORKTREE_ID,
+          agent: 'claude',
+          providerSession: { key: 'session_id', id: 'claude-session-1' },
+          prompt: '',
+          state: 'working',
+          capturedAt: 1,
+          updatedAt: 1,
+          origin: 'live'
+        }
+      }
+    }
+  }
+
+  it.each(Object.keys(exitedAgentRecords))(
+    'offers nothing from a %s record once the agent has exited, though the tab title keeps it',
+    (kind) => {
+      makeState()
+      useAppStore.setState(exitedAgentRecords[kind])
+      const state = useAppStore.getState()
+      expect(
+        resolveTabSessionHistorySubject(state, { tab: { id: 'term-1', worktreeId: WORKTREE_ID } })
+      ).toBeNull()
+      expect(collectAiVaultTitleRequests(state)).toEqual([
+        expect.objectContaining({
+          tabId: 'term-1',
+          providerSession: { key: 'session_id', id: 'claude-session-1' }
+        })
+      ])
+    }
+  )
+
+  it("prefers a split pane's running agent over the focused pane's exited one", () => {
+    makeState({
+      'term-1:leaf-2': makeAgentStatusEntry({
+        agentType: 'claude',
+        paneKey: 'term-1:leaf-2',
+        tabId: 'term-1',
+        worktreeId: WORKTREE_ID,
+        providerSession: { key: 'session_id', id: 'claude-session-1' }
+      })
+    })
+    const exited = makeAgentStatusEntry({
+      agentType: 'claude',
+      paneKey: 'term-1:leaf-1',
+      tabId: 'term-1',
+      worktreeId: WORKTREE_ID,
+      providerSession: { key: 'session_id', id: 'claude-session-old' }
+    })
+    useAppStore.setState({
+      terminalLayoutsByTabId: {
+        'term-1': { root: null, activeLeafId: 'leaf-1', expandedLeafId: null }
+      },
+      retainedAgentsByPaneKey: {
+        'term-1:leaf-1': {
+          entry: exited,
+          worktreeId: WORKTREE_ID,
+          tab: makeTerminalTab('term-1', WORKTREE_ID, 'claude'),
+          agentType: 'claude',
+          startedAt: exited.stateStartedAt
+        }
+      }
+    })
+    expect(
+      resolveTabSessionHistorySubject(useAppStore.getState(), {
+        tab: { id: 'term-1', worktreeId: WORKTREE_ID }
+      })
+    ).toEqual(cliSubject)
+  })
+
   it('looks nothing up over SSH, where neither move is ever offered', () => {
     const state = makeState(liveClaudeEntry, { connectionId: 'dev-box' })
     expect(

src/renderer/src/components/tab-bar/tab-session-history-switch.ts

@@ -91,8 +91,9 @@ export function resolveTabSessionHistorySubject(
       : null
     return target ? { ...target, kind: 'chat', sessionId: args.structuredSessionId } : null
   }
-  // The same pane-to-conversation mapping tab titles use: live agent, then sleeping, then retained.
-  const titleRequest = collectAiVaultTitleRequests(state).find(
+  // The pane-to-conversation mapping tab titles use, limited to agents still running: once the agent
+  // exits, the tab title keeps its conversation but the move is no longer offered.
+  const titleRequest = collectAiVaultTitleRequests(state, { runningAgentsOnly: true }).find(
     (candidate) => candidate.tabId === args.tab.id
   )
   const target = titleRequest ? workspace(titleRequest.worktreeId, 'cli') : null

src/renderer/src/lib/ai-vault-tab-title-requests.ts

@@ -67,15 +67,25 @@ function registerCandidate(
   })
 }
 
-export function collectAiVaultTitleRequests(state: AppState): AiVaultTitleRequest[] {
+export function collectAiVaultTitleRequests(
+  state: AppState,
+  options: {
+    /** Skip retained and sleeping records: those remember a conversation after its agent exited. */
+    runningAgentsOnly?: boolean
+  } = {}
+): AiVaultTitleRequest[] {
   const tabsById = new Map(
     Object.values(state.tabsByWorktree)
       .flat()
       .map((tab) => [tab.id, tab] as const)
   )
   const candidates = new Map<string, RequestCandidate>()
+  const retained = options.runningAgentsOnly ? [] : Object.values(state.retainedAgentsByPaneKey)
+  const sleeping = options.runningAgentsOnly
+    ? []
+    : Object.values(state.sleepingAgentSessionsByPaneKey)
 
-  for (const entry of Object.values(state.retainedAgentsByPaneKey)) {
+  for (const entry of retained) {
     registerCandidate(state, tabsById, candidates, {
       agent: entry.agentType,
       paneKey: entry.entry.paneKey,
@@ -86,7 +96,7 @@ export function collectAiVaultTitleRequests(state: AppState): AiVaultTitleReques
       worktreeId: entry.worktreeId
     })
   }
-  for (const record of Object.values(state.sleepingAgentSessionsByPaneKey)) {
+  for (const record of sleeping) {
     registerCandidate(state, tabsById, candidates, {
       agent: record.agent,
       paneKey: record.paneKey,