fix(mobile): open host editor reliably (#11635)

mobile/app/index.tsx

@@ -26,6 +26,7 @@ import {
 } from '../src/components/AccountUsage'
 import AsyncStorage from '@react-native-async-storage/async-storage'
 import { loadHosts } from '../src/transport/host-store'
+import { navigateToMobileHostEdit } from '../src/transport/host-edit-navigation'
 import { removeHostAndCloseClient } from '../src/transport/host-removal-lifecycle'
 import { pickResumeWorktree } from '../src/worktree/resume-worktree'
 import type { RpcClient } from '../src/transport/rpc-client'
@@ -1010,7 +1011,7 @@ export default function HomeScreen() {
             closeBeforePress: true,
             onPress: () => {
               setActionTarget(null)
-              router.push(`/h/${host.id}/edit`)
+              navigateToMobileHostEdit(router, host.id)
             }
           })
           items.push({

mobile/src/transport/host-edit-navigation.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it, vi } from 'vitest'
+import { mobileHostEditRoute, navigateToMobileHostEdit } from './host-edit-navigation'
+
+describe('mobileHostEditRoute', () => {
+  it('keeps the dynamic host segment explicit for a cold host navigator', () => {
+    expect(mobileHostEditRoute('host-1')).toEqual({
+      pathname: '/h/[hostId]/edit',
+      params: { hostId: 'host-1' }
+    })
+  })
+
+  it('mounts a cold host navigator before replacing its index with edit', () => {
+    let nextFrame: FrameRequestCallback | null = null
+    const push = vi.fn()
+    const replace = vi.fn()
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => {
+      nextFrame = callback
+      return 1
+    })
+
+    navigateToMobileHostEdit({ push, replace }, 'host-1')
+    expect(push).toHaveBeenCalledWith('/h/host-1')
+    expect(replace).not.toHaveBeenCalled()
+
+    nextFrame?.(0)
+    expect(replace).toHaveBeenCalledWith(mobileHostEditRoute('host-1'))
+    vi.unstubAllGlobals()
+  })
+})

mobile/src/transport/host-edit-navigation.ts

@@ -0,0 +1,19 @@
+type HostEditRouter = {
+  push: (href: `/h/${string}`) => void
+  replace: (href: ReturnType<typeof mobileHostEditRoute>) => void
+}
+
+export function mobileHostEditRoute(hostId: string) {
+  return {
+    pathname: '/h/[hostId]/edit' as const,
+    params: { hostId }
+  }
+}
+
+export function navigateToMobileHostEdit(router: HostEditRouter, hostId: string): void {
+  // Why: a cold nested host navigator resolves a deep push to its index route.
+  router.push(`/h/${hostId}`)
+  requestAnimationFrame(() => {
+    router.replace(mobileHostEditRoute(hostId))
+  })
+}