feat: OneNote-style notebooks, text fonts, and page navigation

Add notebook.json containers with multi-member pages, fix PDF text
editing (size/bold/drag/double-tap), index SidecarText in search, and
share keyboard page shortcuts plus a PDF scrubber.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/l10n/app_localizations.dart

@@ -1153,6 +1153,66 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Processing OCR…'**
   String get processingOcr;
+
+  /// No description provided for @notebooksSection.
+  ///
+  /// In en, this message translates to:
+  /// **'Notebooks'**
+  String get notebooksSection;
+
+  /// No description provided for @addBlankPage.
+  ///
+  /// In en, this message translates to:
+  /// **'Blank page'**
+  String get addBlankPage;
+
+  /// No description provided for @importIntoNotebook.
+  ///
+  /// In en, this message translates to:
+  /// **'Import into notebook'**
+  String get importIntoNotebook;
+
+  /// No description provided for @notebookMembersEmpty.
+  ///
+  /// In en, this message translates to:
+  /// **'No pages yet'**
+  String get notebookMembersEmpty;
+
+  /// No description provided for @memberCount.
+  ///
+  /// In en, this message translates to:
+  /// **'{count} items'**
+  String memberCount(int count);
+
+  /// No description provided for @textFontSmall.
+  ///
+  /// In en, this message translates to:
+  /// **'S'**
+  String get textFontSmall;
+
+  /// No description provided for @textFontMedium.
+  ///
+  /// In en, this message translates to:
+  /// **'M'**
+  String get textFontMedium;
+
+  /// No description provided for @textFontLarge.
+  ///
+  /// In en, this message translates to:
+  /// **'L'**
+  String get textFontLarge;
+
+  /// No description provided for @textBold.
+  ///
+  /// In en, this message translates to:
+  /// **'Bold'**
+  String get textBold;
+
+  /// No description provided for @textDragHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Drag to move'**
+  String get textDragHint;
 }
 
 class _AppLocalizationsDelegate