feat: vault-aligned server v1 + UX polish

Redesign the optional FastAPI companion around vault files (manifest /
PUT/GET/DELETE + OCR jobs) instead of legacy strokes_json notes. Wire a
client Server settings panel for health/login. Polish shell UX: l10n for
settings/home/board, sticky-board empty state, and a narrow-screen
diagnostics FAB.

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

lib/l10n/app_localizations.dart

@@ -985,6 +985,174 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Enter a server URL to enable sync.'**
   String get syncNotConfigured;
+
+  /// No description provided for @settingsDefaults.
+  ///
+  /// In en, this message translates to:
+  /// **'Defaults'**
+  String get settingsDefaults;
+
+  /// No description provided for @settingsAppearance.
+  ///
+  /// In en, this message translates to:
+  /// **'Appearance'**
+  String get settingsAppearance;
+
+  /// No description provided for @settingsAbout.
+  ///
+  /// In en, this message translates to:
+  /// **'About'**
+  String get settingsAbout;
+
+  /// No description provided for @settingsDefaultTool.
+  ///
+  /// In en, this message translates to:
+  /// **'Default tool'**
+  String get settingsDefaultTool;
+
+  /// No description provided for @settingsDefaultColor.
+  ///
+  /// In en, this message translates to:
+  /// **'Default color'**
+  String get settingsDefaultColor;
+
+  /// No description provided for @settingsDefaultWidth.
+  ///
+  /// In en, this message translates to:
+  /// **'Default stroke width'**
+  String get settingsDefaultWidth;
+
+  /// No description provided for @settingsPressureCurve.
+  ///
+  /// In en, this message translates to:
+  /// **'Pressure curve'**
+  String get settingsPressureCurve;
+
+  /// No description provided for @settingsClearConfirmBody.
+  ///
+  /// In en, this message translates to:
+  /// **'This resets pen defaults and appearance. Notes and documents are not affected.'**
+  String get settingsClearConfirmBody;
+
+  /// No description provided for @serverSection.
+  ///
+  /// In en, this message translates to:
+  /// **'BadNote Server'**
+  String get serverSection;
+
+  /// No description provided for @serverUrl.
+  ///
+  /// In en, this message translates to:
+  /// **'Server URL'**
+  String get serverUrl;
+
+  /// No description provided for @serverUrlHint.
+  ///
+  /// In en, this message translates to:
+  /// **'http://192.168.1.10:8080'**
+  String get serverUrlHint;
+
+  /// No description provided for @serverUsername.
+  ///
+  /// In en, this message translates to:
+  /// **'Username'**
+  String get serverUsername;
+
+  /// No description provided for @serverPassword.
+  ///
+  /// In en, this message translates to:
+  /// **'Password'**
+  String get serverPassword;
+
+  /// No description provided for @serverSave.
+  ///
+  /// In en, this message translates to:
+  /// **'Save & sign in'**
+  String get serverSave;
+
+  /// No description provided for @serverTest.
+  ///
+  /// In en, this message translates to:
+  /// **'Test connection'**
+  String get serverTest;
+
+  /// No description provided for @serverTestOk.
+  ///
+  /// In en, this message translates to:
+  /// **'Connected · API {version}'**
+  String serverTestOk(String version);
+
+  /// No description provided for @serverTestFail.
+  ///
+  /// In en, this message translates to:
+  /// **'Connection failed: {error}'**
+  String serverTestFail(String error);
+
+  /// No description provided for @serverLoggedIn.
+  ///
+  /// In en, this message translates to:
+  /// **'Signed in'**
+  String get serverLoggedIn;
+
+  /// No description provided for @serverHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Optional. Self-hosted vault assist + deferred OCR; notes stay fully offline.'**
+  String get serverHint;
+
+  /// No description provided for @boardEmptyTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'No sticky notes yet'**
+  String get boardEmptyTitle;
+
+  /// No description provided for @boardEmptyBody.
+  ///
+  /// In en, this message translates to:
+  /// **'Tap + to add a card. Write [[other-card-id]] in the body to create a backlink.'**
+  String get boardEmptyBody;
+
+  /// No description provided for @relativeJustNow.
+  ///
+  /// In en, this message translates to:
+  /// **'Just now'**
+  String get relativeJustNow;
+
+  /// No description provided for @relativeMinutesAgo.
+  ///
+  /// In en, this message translates to:
+  /// **'{n}m ago'**
+  String relativeMinutesAgo(int n);
+
+  /// No description provided for @relativeHoursAgo.
+  ///
+  /// In en, this message translates to:
+  /// **'{n}h ago'**
+  String relativeHoursAgo(int n);
+
+  /// No description provided for @relativeYesterday.
+  ///
+  /// In en, this message translates to:
+  /// **'Yesterday'**
+  String get relativeYesterday;
+
+  /// No description provided for @diagExported.
+  ///
+  /// In en, this message translates to:
+  /// **'Diagnostic pack exported ({bytes} bytes)\nPath copied'**
+  String diagExported(int bytes);
+
+  /// No description provided for @diagExportFail.
+  ///
+  /// In en, this message translates to:
+  /// **'Export failed: {error}'**
+  String diagExportFail(String error);
+
+  /// No description provided for @processingOcr.
+  ///
+  /// In en, this message translates to:
+  /// **'Processing OCR…'**
+  String get processingOcr;
 }
 
 class _AppLocalizationsDelegate