fix(terminal): do not let a stranded binding block another tab's relay wake

The binder index read the raw map, so a binding whose leaf had already left the
tree — one that reattaches nothing — was enough to withhold a different tab's
remote session restore, and the user silently lost it. The index now counts only
leaves the layout owns, which is the same rule the ownership lookup applies.

src/renderer/src/store/terminals/workspace-terminal-duplicate-binding-reconnect.test.ts

@@ -204,6 +204,30 @@ describe('hydrating the STA-7961 duplicate binding', () => {
     await expect(rowPtyIdsAfterReconnect(session)).resolves.toEqual([SHARED_PTY_ID, null])
   })
 
+  it('still wakes a relay session only a stranded binding names', async () => {
+    // The split tab's map still names the pty at a leaf its tree dropped, so it reattaches
+    // nothing. Blocking on that would cost the single tab a real remote restore for no gain.
+    const strandedPty = 'repo1::/wt-1@@relay-stranded'
+    const base = duplicateLeafSession()
+    const splitLayout = base.terminalLayoutsByTabId[SPLIT_TAB_ID]!
+    const session: WorkspaceSessionState = {
+      ...base,
+      remoteSessionIdsByTabId: { [SINGLE_TAB_ID]: strandedPty },
+      terminalLayoutsByTabId: {
+        ...base.terminalLayoutsByTabId,
+        [SPLIT_TAB_ID]: {
+          ...splitLayout,
+          ptyIdsByLeafId: {
+            ...splitLayout.ptyIdsByLeafId,
+            'ac1f6d20-1f3e-4c58-8f2b-0a9e7d4c3b15': strandedPty
+          }
+        }
+      }
+    }
+
+    expect(hydrate(session).pendingReconnectPtyIdByTabId[SINGLE_TAB_ID]).toBe(strandedPty)
+  })
+
   it('still wakes a relay session nothing else binds', async () => {
     const session = {
       ...duplicateLeafSession(),

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

@@ -2,6 +2,7 @@ import type { Repo } from '../../../../shared/repo-types'
 import type { TerminalLayoutSnapshot } from '../../../../shared/terminal-tab-types'
 import type { Worktree } from '../../../../shared/worktree/types'
 import type { WorkspaceSessionState } from '../../../../shared/workspace-session-state-types'
+import { collectOwnedLeafIds } from '@/components/terminal-pane/terminal-layout-leaf-claims'
 import { buildByIdIndex, buildWorktreeByIdIndex } from '../slices/worktree-by-id-index'
 import { resolvePrimaryLayoutPtyId } from './terminal-pty-identities'
 
@@ -81,9 +82,19 @@ export function buildWorkspaceTerminalReconnectPlan({
   // Why indexed: the relay wake handle is a separate fact from the layout, but it must not hand a
   // tab the very PTY another tab's healed layout binds — that is the duplicate mount reached
   // through a second door. A wake nothing else binds is untouched, which is every normal one.
+  //
+  // Why owned leaves only: a binding whose leaf left the tree reattaches nothing, so blocking on
+  // it would cost a real remote session its restore for no gain. And why an id match is enough:
+  // the row, the leaf binding and the relay handle are all written from one spawn id
+  // (`updateTabPtyId`) and rewritten together by `ssh-target-id-migration.ts`, so the index
+  // cannot miss on id form.
   const tabIdsBindingPtyId = new Map<string, Set<string>>()
   for (const [tabId, layout] of Object.entries(layoutsByTabId)) {
-    for (const ptyId of Object.values(layout.ptyIdsByLeafId ?? {})) {
+    const ownedLeafIds = collectOwnedLeafIds(layout)
+    for (const [leafId, ptyId] of Object.entries(layout.ptyIdsByLeafId ?? {})) {
+      if (!ptyId || !ownedLeafIds.has(leafId)) {
+        continue
+      }
       const binders = tabIdsBindingPtyId.get(ptyId)
       if (binders) {
         binders.add(tabId)