fix: live-reload theme CSS vars on editor save and frontmatter changes

Wire notifyThemeSaved through the frontmatter update chain so CSS
variables update immediately when:
- The user edits a theme note in raw mode and presses Cmd+S
- A frontmatter property is changed via the inspector panel

Also expose CodeMirror EditorView on the DOM for Playwright test access,
add unit tests for onNotePersisted, and a new Playwright smoke test
that verifies the full raw-editor → save → CSS-vars-update flow.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/hooks/useEditorSave.test.ts

@@ -219,6 +219,43 @@ describe('useEditorSave', () => {
     expect(updateVaultContent).toHaveBeenCalledWith('/vault/note.md', edited)
   })
 
+  it('calls onNotePersisted with path and content after saving pending content', async () => {
+    const onNotePersisted = vi.fn()
+    const { result } = renderHook(() =>
+      useEditorSave({ updateVaultContent, setTabs, setToastMessage, onNotePersisted })
+    )
+
+    act(() => {
+      result.current.handleContentChange('/vault/theme/default.md', '---\nbackground: "#FFD700"\n---\n')
+    })
+
+    await act(async () => {
+      await result.current.handleSave()
+    })
+
+    expect(onNotePersisted).toHaveBeenCalledWith(
+      '/vault/theme/default.md',
+      '---\nbackground: "#FFD700"\n---\n',
+    )
+  })
+
+  it('calls onNotePersisted for unsaved fallback when no pending content', async () => {
+    const onNotePersisted = vi.fn()
+    const { result } = renderHook(() =>
+      useEditorSave({ updateVaultContent, setTabs, setToastMessage, onNotePersisted })
+    )
+
+    // No handleContentChange — simulate Cmd+S on a newly created unsaved note
+    await act(async () => {
+      await result.current.handleSave({ path: '/vault/theme/default.md', content: '---\nbackground: "#FF0000"\n---\n' })
+    })
+
+    expect(onNotePersisted).toHaveBeenCalledWith(
+      '/vault/theme/default.md',
+      '---\nbackground: "#FF0000"\n---\n',
+    )
+  })
+
   it('successive edits and saves persist each version correctly', async () => {
     const { result } = renderSaveHook()