fix(desktop): tighten remote filesystem wiring

apps/desktop/src/app/chat/right-rail/preview-pane.test.tsx

@@ -1,11 +1,50 @@
 import { act, cleanup, render } from '@testing-library/react'
-import { afterEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { $connection } from '@/store/session'
 
 import { PreviewPane } from './preview-pane'
 
 describe('PreviewPane console state', () => {
+  beforeEach(() => {
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => window.setTimeout(() => callback(Date.now()), 0))
+    vi.stubGlobal('cancelAnimationFrame', (id: number) => window.clearTimeout(id))
+  })
+
   afterEach(() => {
     cleanup()
+    $connection.set(null)
+    vi.unstubAllGlobals()
+  })
+
+  it('does not watch backend-only remote filesystem previews locally', () => {
+    const watchPreviewFile = vi.fn(async () => ({ id: 'watch-1', path: '/remote/file.txt' }))
+    const onPreviewFileChanged = vi.fn(() => vi.fn())
+    $connection.set({ mode: 'remote' } as never)
+    vi.stubGlobal('window', {
+      ...window,
+      hermesDesktop: {
+        onPreviewFileChanged,
+        watchPreviewFile
+      }
+    })
+
+    render(
+      <PreviewPane
+        setTitlebarToolGroup={vi.fn()}
+        target={{
+          kind: 'file',
+          label: 'file.txt',
+          path: '/remote/file.txt',
+          previewKind: 'text',
+          source: '/remote/file.txt',
+          url: 'file:///remote/file.txt'
+        }}
+      />
+    )
+
+    expect(watchPreviewFile).not.toHaveBeenCalled()
+    expect(onPreviewFileChanged).not.toHaveBeenCalled()
   })
 
   it('does not rebuild the pane titlebar group for streamed console logs', () => {

apps/desktop/src/app/chat/right-rail/preview-pane.tsx

@@ -5,6 +5,7 @@ import { useCallback, useEffect, useRef, useState } from 'react'
 import type { SetTitlebarToolGroup, TitlebarTool } from '@/app/shell/titlebar-controls'
 import { Tip } from '@/components/ui/tooltip'
 import { type Translations, useI18n } from '@/i18n'
+import { isDesktopFsRemoteMode } from '@/lib/desktop-fs'
 import { Bug } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 import { notify, notifyError } from '@/store/notifications'
@@ -406,6 +407,7 @@ export function PreviewPane({
   useEffect(() => {
     if (
       target.kind !== 'file' ||
+      isDesktopFsRemoteMode() ||
       !window.hermesDesktop?.watchPreviewFile ||
       !window.hermesDesktop?.onPreviewFileChanged
     ) {

apps/desktop/src/app/right-sidebar/files/ipc.ts

@@ -97,7 +97,7 @@ async function gitignoreFor(dir: string) {
   let cached = gitignoreCache.get(key)
 
   if (!cached) {
-    cached = readGitignore(key)
+    cached = readGitignore(clean(dir))
     gitignoreCache.set(key, cached)
   }
 

apps/desktop/src/app/right-sidebar/files/use-project-tree.test.ts

@@ -1,19 +1,24 @@
-import { act, renderHook, waitFor } from '@testing-library/react'
+import { act, cleanup, renderHook, waitFor } from '@testing-library/react'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 
+import { $connection } from '@/store/session'
 import type { HermesReadDirResult } from '@/global'
 
+import { clearProjectDirCache, readProjectDir } from './ipc'
 import { resetProjectTreeState, useProjectTree } from './use-project-tree'
 
 const readDir = vi.fn<(path: string) => Promise<HermesReadDirResult>>()
 
 beforeEach(() => {
+  $connection.set(null)
   resetProjectTreeState()
   readDir.mockReset()
   ;(window as unknown as { hermesDesktop: { readDir: typeof readDir } }).hermesDesktop = { readDir }
 })
 
 afterEach(() => {
+  cleanup()
+  $connection.set(null)
   resetProjectTreeState()
   delete (window as unknown as { hermesDesktop?: unknown }).hermesDesktop
 })
@@ -106,6 +111,36 @@ describe('useProjectTree', () => {
     expect(readDir).toHaveBeenCalledTimes(1)
   })
 
+  it('reads gitignore from the real path while caching per connection', async () => {
+    const readFileDataUrl = vi.fn(async () => `data:text/plain;base64,${btoa('ignored.log\n')}`)
+    const gitRoot = vi.fn(async () => '/repo')
+    readDir.mockImplementation(async path => {
+      if (path === '/repo') return ok([{ name: '.gitignore', path: '/repo/.gitignore', isDirectory: false }])
+      if (path === '/repo/src') {
+        return ok([
+          { name: 'app.ts', path: '/repo/src/app.ts', isDirectory: false },
+          { name: 'ignored.log', path: '/repo/src/ignored.log', isDirectory: false }
+        ])
+      }
+      throw new Error(`unexpected path ${path}`)
+    })
+    ;(window as unknown as { hermesDesktop: unknown }).hermesDesktop = { gitRoot, readDir, readFileDataUrl }
+
+    $connection.set({ baseUrl: 'local-a', mode: 'local' } as never)
+    await expect(readProjectDir('/repo/src', '/repo')).resolves.toMatchObject({
+      entries: [{ name: 'app.ts', path: '/repo/src/app.ts', isDirectory: false }]
+    })
+    expect(readDir).toHaveBeenCalledWith('/repo')
+    expect(readDir).not.toHaveBeenCalledWith(expect.stringContaining('local-a'))
+
+    $connection.set({ baseUrl: 'local-b', mode: 'local' } as never)
+    clearProjectDirCache()
+    await expect(readProjectDir('/repo/src', '/repo')).resolves.toMatchObject({
+      entries: [{ name: 'app.ts', path: '/repo/src/app.ts', isDirectory: false }]
+    })
+    expect(readDir.mock.calls.filter(([path]) => path === '/repo')).toHaveLength(2)
+  })
+
   it('captures per-folder error code and shows an error placeholder child', async () => {
     readDir.mockResolvedValueOnce(ok([{ name: 'priv', path: '/p/priv', isDirectory: true }]))
     readDir.mockResolvedValueOnce({ entries: [], error: 'EACCES' })

apps/desktop/src/lib/desktop-fs.test.ts

@@ -85,7 +85,7 @@ describe('desktop filesystem facade', () => {
     expect(gitRoot).not.toHaveBeenCalled()
   })
 
-  it('uses the registered in-app picker in remote mode', async () => {
+  it('uses the registered in-app directory picker in remote mode', async () => {
     const remoteSelect = vi.fn(async () => ['/remote/project'])
     $connection.set({ mode: 'remote' } as never)
     setDesktopFsRemotePicker({ selectPaths: remoteSelect })
@@ -97,4 +97,16 @@ describe('desktop filesystem facade', () => {
     expect(remoteSelect).toHaveBeenCalledWith({ defaultPath: '/remote', directories: true, multiple: false })
     expect(selectPaths).not.toHaveBeenCalled()
   })
+
+  it('does not treat the remote directory picker as a general file picker', async () => {
+    const remoteSelect = vi.fn(async () => ['/remote/project'])
+    $connection.set({ mode: 'remote' } as never)
+    setDesktopFsRemotePicker({ selectPaths: remoteSelect })
+
+    await expect(selectDesktopPaths({ directories: false, multiple: false })).resolves.toEqual([])
+    await expect(selectDesktopPaths({ directories: true, multiple: true })).resolves.toEqual([])
+
+    expect(remoteSelect).not.toHaveBeenCalled()
+    expect(selectPaths).not.toHaveBeenCalled()
+  })
 })

apps/desktop/src/lib/desktop-fs.ts

@@ -80,5 +80,8 @@ export async function selectDesktopPaths(options?: HermesSelectPathsOptions): Pr
   if (!isDesktopFsRemoteMode()) {
     return desktop.selectPaths(options)
   }
+  if (!options?.directories || options.multiple !== false) {
+    return []
+  }
   return remotePicker ? remotePicker.selectPaths(options) : []
 }