fix(editor): scope default-pane reading positions by file owner (#34816)

Same-path files with different owners (runtime hosts or worktrees) shared
Monaco, rich-markdown, notebook, and PDF/media reading positions when the
tab id equals the file id. Key them by file id, matching the diff and
markdown preview keys.

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>

src/renderer/src/components/editor/EditorContent.monaco-lifecycle.test.tsx

@@ -2,10 +2,12 @@
 import { cleanup, render } from '@testing-library/react'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { OpenFile } from '@/store/slices/editor'
+import { buildOwnedEditorFileId } from '@/store/slices/editor/file-ids/editor-file-ids'
 
 const lifecycle = vi.hoisted(() => ({
   events: [] as string[],
   diffModelKeys: [] as string[],
+  viewStateKeys: new Array<string>(),
   models: new Map<string, { content: string; undo: string[] }>(),
   notebookProps: [] as {
     fileId: string
@@ -70,7 +72,9 @@ vi.mock('@/lib/lazy-with-retry', async () => {
         readOnly?: boolean
         liveTail?: boolean
         viewStateId?: string
+        viewStateKey: string
       }) {
+        lifecycle.viewStateKeys.push(props.viewStateKey)
         /* oxlint-disable react-hooks/exhaustive-deps -- Mount-only by design: a prop-effect would hide a missing outer React remount. */
         React.useEffect(() => {
           lifecycle.events.push(`mount:${props.filePath}`)
@@ -215,6 +219,7 @@ afterEach(() => {
   cleanup()
   lifecycle.events.length = 0
   lifecycle.diffModelKeys.length = 0
+  lifecycle.viewStateKeys.length = 0
   lifecycle.models.clear()
   lifecycle.mountedProps.length = 0
   lifecycle.notebookProps.length = 0
@@ -222,6 +227,28 @@ afterEach(() => {
 })
 
 describe('EditorContent Monaco lifecycle boundary', () => {
+  it('keeps default-pane view state separate for the same path on different runtime hosts', () => {
+    const filePath = '/repo/main.ts'
+    const worktreeId = 'repo::/repo'
+    const first = file(filePath, {
+      id: buildOwnedEditorFileId(filePath, worktreeId, 'host-a'),
+      runtimeEnvironmentId: 'host-a'
+    })
+    const second = file(filePath, {
+      id: buildOwnedEditorFileId(filePath, worktreeId, 'host-b'),
+      runtimeEnvironmentId: 'host-b'
+    })
+    const view = render(
+      <EditorContent {...props(first, 'first host')} viewStateScopeId={first.id} />
+    )
+    const firstKey = lifecycle.viewStateKeys.at(-1)
+    expect(firstKey).toBeTypeOf('string')
+
+    view.rerender(<EditorContent {...props(second, 'second host')} viewStateScopeId={second.id} />)
+
+    expect(lifecycle.viewStateKeys.at(-1)).not.toBe(firstKey)
+  })
+
   it('unmounts the prior path before reconciling a stale retained target model', () => {
     const first = file('/repo/first.ts')
     const second = file('/repo/second.ts')

src/renderer/src/components/editor/EditorContent.tsx

@@ -98,7 +98,7 @@ export function EditorContent({
 }): React.JSX.Element {
   const editorViewStateKey =
     viewStateScopeId === activeFile.id
-      ? activeFile.filePath
+      ? activeFile.id
       : `${activeFile.filePath}::${viewStateScopeId}`
   const diffViewStateKey =
     viewStateScopeId === activeFile.id ? activeFile.id : `${activeFile.id}::${viewStateScopeId}`
@@ -109,7 +109,7 @@ export function EditorContent({
   // Why: only the single-pane edit path gets PDF scroll memory — diff and conflict review mount several viewers on one path.
   const pdfViewStateKey =
     viewStateScopeId === activeFile.id
-      ? `${activeFile.filePath}:pdf`
+      ? `${activeFile.id}:pdf`
       : `${activeFile.filePath}::${viewStateScopeId}:pdf`
   // Scope durable PDF zoom by owner: identical paths can belong to different worktrees or remote hosts.
   const pdfPreferenceKey = buildPdfScalePreferenceKey(activeFile)