fix(terminal): let a layout that carries the leaf beat the spawn-time tab hint

src/renderer/src/hooks/terminal-reveal-duplicate-leaf-mint.test.ts

@@ -2,6 +2,7 @@
 // identity, and the renderer delivers PTY data to one handler slot per pty id — so one pane
 // starves and both fight over the grid size. That is STA-7961.
 import { describe, expect, it } from 'vitest'
+import { collectLeafIdsInOrder } from '@/components/terminal-pane/terminal-layout-leaf-ids'
 import {
   createHarnessStoreState,
   createStoreWithOwnerFiledElsewhere,
@@ -98,4 +99,53 @@ describe('terminal reveal must not mint a tab that reuses a bound leaf id (STA-7
     expect(storeState.createTab).not.toHaveBeenCalled()
     expect(tabsBindingSharedLeaf(storeState)).toEqual(['tab-a'])
   })
+
+  it('adopts the tab whose layout carries the leaf over the tab the pty was minted against', async () => {
+    // The hint is a spawn-time tab id, not a binding. tab-b already holds the leaf, so reusing
+    // the hinted tab-a writes a single pane over its split and orphans leaf-a2's pty.
+    const storeState: HarnessStoreState = createHarnessStoreState({
+      tabsByWorktree: {
+        [WORKTREE_ID]: [
+          { id: 'tab-a', ptyId: 'pty-a1', title: 'Terminal 1' },
+          { id: 'tab-b', ptyId: null, title: 'Terminal 2' }
+        ]
+      },
+      ptyIdsByTabId: {},
+      terminalLayoutsByTabId: {
+        'tab-a': {
+          root: {
+            type: 'split',
+            direction: 'horizontal',
+            first: { type: 'leaf', leafId: 'leaf-a1' },
+            second: { type: 'leaf', leafId: 'leaf-a2' }
+          },
+          ptyIdsByLeafId: { 'leaf-a1': 'pty-a1', 'leaf-a2': 'pty-a2' }
+        },
+        // Bound to a dead pty, so the revealed pty is still owned by nobody.
+        'tab-b': {
+          root: { type: 'leaf', leafId: SHARED_LEAF_ID },
+          ptyIdsByLeafId: { [SHARED_LEAF_ID]: 'pty-stale' }
+        }
+      }
+    })
+    const harness = await loadIpcEventsHarness(storeState)
+    harness.useIpcEvents()
+
+    harness.createTerminal({
+      requestId: 'reveal',
+      worktreeId: WORKTREE_ID,
+      ptyId: SHARED_PTY_ID,
+      tabId: 'tab-a',
+      leafId: SHARED_LEAF_ID,
+      presentation: 'focused',
+      title: 'OpenCode'
+    })
+
+    expect(harness.replyTerminalCreate.mock.calls[0]?.[0]).toMatchObject({ tabId: 'tab-b' })
+    expect(storeState.createTab).not.toHaveBeenCalled()
+    expect(tabsBindingSharedLeaf(storeState)).toEqual(['tab-b'])
+    const hintedLayout = storeState.terminalLayoutsByTabId['tab-a']!
+    expect(collectLeafIdsInOrder(hintedLayout.root ?? null)).toEqual(['leaf-a1', 'leaf-a2'])
+    expect(hintedLayout.ptyIdsByLeafId).toEqual({ 'leaf-a1': 'pty-a1', 'leaf-a2': 'pty-a2' })
+  })
 })

src/renderer/src/lib/terminal-reveal-tab-adoption.ts

@@ -53,11 +53,6 @@ export function resolveTerminalRevealTabAdoption(
   if (ownership.kind === 'owned') {
     return ownership.owner.tabId
   }
-  // Why: nothing holds the PTY yet, so the tab it was minted against is the only thing left that
-  // keeps paneKey hook attribution intact (#10486), and a split names its parent by that id.
-  if (ownership.kind === 'none' && hintTabId !== undefined) {
-    return hintTabId
-  }
   // STA-7961: the PTY is unowned here, but the leaf id may already be someone's pane.
   const leafOwnerTabId = request.leafId
     ? findTerminalTabIdBindingLeafId(state, request.leafId)
@@ -65,6 +60,13 @@ export function resolveTerminalRevealTabAdoption(
   if (leafOwnerTabId !== null) {
     return leafOwnerTabId
   }
+  // Why: nothing holds the PTY yet, so the tab it was minted against is the only thing left that
+  // keeps paneKey hook attribution intact (#10486), and a split names its parent by that id. It
+  // ranks below the leaf owner because a layout already carrying the leaf is that pane's home,
+  // and reusing the hinted tab instead writes a single pane over it and orphans the rest.
+  if (ownership.kind === 'none' && hintTabId !== undefined) {
+    return hintTabId
+  }
   // Why mint even when claimants exist: no layout carries this leaf id, so the bridge would
   // replace the adopted tab's whole layout with a single pane and orphan its other panes' PTYs.
   const claim =