Merge branch 'stack-preview' into stack-reconcile

# Conflicts:
#	src/renderer/src/components/editor/editor-panel-render-model.ts

src/renderer/src/components/editor/EditorPanelShell.header.test.tsx

@@ -10,7 +10,11 @@ vi.mock('./EditorPanelHeader', () => ({
 }))
 
 vi.mock('./EditorContent', () => ({
-  EditorContent: () => <div data-editor-content />
+  EditorContent: ({ onOpenMarkdownPreview }: { onOpenMarkdownPreview?: () => void }) => (
+    <div data-editor-content>
+      {onOpenMarkdownPreview && <button onClick={onOpenMarkdownPreview}>Open preview</button>}
+    </div>
+  )
 }))
 
 vi.mock('./UntitledFileRenameDialog', () => ({
@@ -48,7 +52,7 @@ function renderShell(file: OpenFile, isCombinedDiff = false): string {
     availableEditorToggleModes: [],
     effectiveToggleValue: 'edit',
     canOpenPreviewToSide: false,
-    canShowMarkdownPreview: false,
+    canShowMarkdownPreview: file.language === 'markdown' && file.mode === 'edit',
     canShowMarkdownTableOfContents: false,
     isMarkdownTableOfContentsDisabled: false,
     shouldShowMarkdownExportAction: false,
@@ -122,3 +126,9 @@ describe('EditorPanelShell path header', () => {
     expect(renderShell(openFile('edit'))).toContain('data-editor-content')
   })
 })
+
+it('offers Markdown preview through the shell even when HTML side preview is unavailable', () => {
+  const file = { ...openFile('edit'), language: 'markdown' }
+  expect(renderShell(file)).toContain('Open preview')
+  expect(renderShell(openFile('edit'))).not.toContain('Open preview')
+})

src/renderer/src/components/editor/EditorPanelShell.tsx

@@ -163,7 +163,7 @@ export function EditorPanelShell({
           showMarkdownFrontmatter={markdownFrontmatterVisible}
           onCloseMarkdownTableOfContents={onCloseMarkdownTableOfContents}
           markdownAnnotationsEnabled={markdownAnnotationsEnabled}
-          onOpenMarkdownPreview={model.canOpenPreviewToSide ? onOpenMarkdownPreview : undefined}
+          onOpenMarkdownPreview={model.canShowMarkdownPreview ? onOpenMarkdownPreview : undefined}
         />
       </Suspense>
       <UntitledFileRenameDialog

src/renderer/src/components/editor/editor-panel-render-model.test.ts

@@ -306,10 +306,11 @@ describe('getEditorPanelRenderModel markdown export affordance', () => {
   })
 })
 
-it('hides disk preview while a fallback draft is unsaved', () => {
+it('offers the live Markdown preview while a fallback draft is unsaved', () => {
   const model = renderModel({
     editorDrafts: { '/repo/README.md': '[reference]: https://example.com' }
   })
-  expect(model.availableEditorToggleModes).not.toContain('preview')
+  expect(model.availableEditorToggleModes).toContain('preview')
+  expect(model.canShowMarkdownPreview).toBe(true)
   expect(model.canOpenPreviewToSide).toBe(false)
 })

src/renderer/src/components/editor/editor-panel-render-model.ts

@@ -144,16 +144,11 @@ export function getEditorPanelRenderModel({
     richModeEligibility !== null
       ? richModeEligibility.exceedsSizeLimit || richModeUnsupportedMessage !== null
       : richModeFaultedForCurrentContent
-  const hasUnsavedMarkdownDraft =
-    viewerLanguage === 'markdown' &&
-    activeFile.mode === 'edit' &&
-    editorDrafts[activeFile.id] !== undefined &&
-    editorDrafts[activeFile.id] !== inlineFileContent?.content
   const editorToggleModes = getEditorToggleModes({
     language: viewerLanguage,
     mode: activeFile.mode,
     diffSource: activeFile.diffSource,
-    richModeFallsBackToSource: richModeFallsBackToSource && !hasUnsavedMarkdownDraft
+    richModeFallsBackToSource
   })
   const availableEditorToggleModes =
     isBinaryEditSurface || !canUseChangesModeForFile(activeFile)
@@ -205,7 +200,6 @@ export function getEditorPanelRenderModel({
     // files and commit diffs whose content may not match the working tree).
     canOpenPreviewToSide:
       canOpenWorkspaceFileBrowser &&
-      !hasUnsavedMarkdownDraft &&
       canPreviewLanguage(viewerLanguage) &&
       (activeFile.mode === 'edit' || (isSingleDiff && openFileState.canOpen)),
     mdViewMode,