fix(layout): tab reconcile and terminal reconnect stop writing tab structure (dark, layout-owner build only)

Main's frames draw the tab bar and rows: reconcile still returns its counts but writes nothing,
and reconnect still advertises restored terminals but leaves the rows to main.

src/renderer/src/store/slices/tabs/layout-owner-shared-path-gates.test.ts

@@ -0,0 +1,69 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { createTabsSliceMockApi } from '../tabs-slice-test-harness'
+import { createTestStore, makeTab } from '../store-test-helpers'
+
+vi.mock('sonner', () => ({ toast: { info: vi.fn(), success: vi.fn(), error: vi.fn() } }))
+vi.mock('../../../../../shared/layout-owner-switch', () => ({ ORCA_LAYOUT_OWNER_IS_MAIN: true }))
+
+createTabsSliceMockApi()
+
+const WT = 'repo1::/tmp/feature'
+
+// Main draws the tab bar from its frames; these shared paths must not write structure of their own.
+describe('shared tab paths in a layout-owner build', () => {
+  let store: ReturnType<typeof createTestStore>
+
+  beforeEach(() => {
+    store = createTestStore()
+  })
+
+  it('reconcile counts what would render and leaves the tab bar to main', () => {
+    const entry = {
+      id: 'stale-terminal',
+      entityId: 'stale-terminal',
+      groupId: 'g-1',
+      worktreeId: WT,
+      contentType: 'terminal' as const,
+      label: 'Terminal 1',
+      customLabel: null,
+      color: null,
+      sortOrder: 0,
+      createdAt: 1
+    }
+    store.setState({
+      unifiedTabsByWorktree: { [WT]: [entry] },
+      groupsByWorktree: {
+        [WT]: [{ id: 'g-1', worktreeId: WT, activeTabId: entry.id, tabOrder: [entry.id] }]
+      },
+      activeGroupIdByWorktree: { [WT]: 'g-1' },
+      tabsByWorktree: { [WT]: [] }
+    })
+    const before = store.getState()
+
+    expect(store.getState().reconcileWorktreeTabModel(WT)).toEqual({
+      renderableTabCount: 0,
+      activeRenderableTabId: null
+    })
+    store.getState().reconcileWorktreeTabModels([WT])
+
+    expect(store.getState().unifiedTabsByWorktree).toBe(before.unifiedTabsByWorktree)
+    expect(store.getState().groupsByWorktree).toBe(before.groupsByWorktree)
+  })
+
+  it('reconnect advertises restored terminals without rewriting their rows', async () => {
+    const rows = { [WT]: [makeTab({ id: 'tab-1', worktreeId: WT, ptyId: null })] }
+    store.setState({
+      tabsByWorktree: rows,
+      terminalLayoutsByTabId: {},
+      pendingReconnectWorktreeIds: [WT],
+      pendingReconnectTabByWorktree: { [WT]: ['tab-1'] },
+      pendingReconnectPtyIdByTabId: { 'tab-1': 'pty-1' }
+    })
+
+    await store.getState().reconnectPersistedTerminals()
+
+    expect(store.getState().ptyIdsByTabId['tab-1']).toEqual(['pty-1'])
+    expect(store.getState().tabsByWorktree).toBe(rows)
+    expect(store.getState().workspaceSessionReady).toBe(true)
+  })
+})

src/renderer/src/store/slices/tabs/tabs-session-actions.ts

@@ -10,6 +10,7 @@ import { buildHydratedTabState } from '../tabs-hydration'
 import { projectWorktreeTabModelReconciliation } from './tabs-reconciliation'
 import { createWorktreeTabModelReconciliationBatch } from './tabs-reconciliation-batch'
 import type { AppState } from '../../types'
+import { ORCA_LAYOUT_OWNER_IS_MAIN } from '../../../../../shared/layout-owner-switch'
 
 function replaceWorkspaceRecordKeys<T>(
   current: Record<string, T>,
@@ -59,6 +60,10 @@ export function createTabsSessionActions(
       if (worktreeIds.length === 0) {
         return
       }
+      // Switch point: main's frames draw the tab bar, so reconcile writes no structure of its own.
+      if (ORCA_LAYOUT_OWNER_IS_MAIN) {
+        return
+      }
       const patch = projectWorktreeTabModelReconciliations(get(), worktreeIds)
       if (Object.keys(patch).length > 0) {
         set(patch)
@@ -67,7 +72,8 @@ export function createTabsSessionActions(
 
     reconcileWorktreeTabModel: (worktreeId) => {
       const reconciliation = projectWorktreeTabModelReconciliation(get(), worktreeId)
-      if (Object.keys(reconciliation.patch).length > 0) {
+      // Switch point: the counts only; main's frames draw the tab bar.
+      if (!ORCA_LAYOUT_OWNER_IS_MAIN && Object.keys(reconciliation.patch).length > 0) {
         set(reconciliation.patch)
       }
       return {

src/renderer/src/store/terminals/workspace-terminal-reconnect.ts

@@ -2,6 +2,7 @@ import type { TerminalTab } from '../../../../shared/terminal-tab-types'
 import { buildByIdIndex, buildWorktreeByIdIndex } from '../slices/worktree-by-id-index'
 import { getRepoIdFromWorktreeId } from '../../../../shared/worktree/id'
 import type { TerminalSlice, TerminalStoreGet, TerminalStoreSet } from './terminal-state'
+import { ORCA_LAYOUT_OWNER_IS_MAIN } from '../../../../shared/layout-owner-switch'
 
 export function createWorkspaceTerminalReconnectActions(
   set: TerminalStoreSet,
@@ -117,7 +118,10 @@ export function createWorkspaceTerminalReconnectActions(
         return
       }
       set({
-        ...(reconnectedTabsByWorktree ? { tabsByWorktree: reconnectedTabsByWorktree } : {}),
+        // Switch point: main's frames draw the rows, with main's own bindings.
+        ...(reconnectedTabsByWorktree && !ORCA_LAYOUT_OWNER_IS_MAIN
+          ? { tabsByWorktree: reconnectedTabsByWorktree }
+          : {}),
         ...(reconnectedPtyIdsByTabId ? { ptyIdsByTabId: reconnectedPtyIdsByTabId } : {}),
         workspaceSessionReady: true,
         pendingReconnectWorktreeIds: [],