fix(todo): the permission to notify asked wherever a reminder is planned, and Settings saying while it is off (ADR 0033, D31)

On a fresh install Todo's reminders never showed: the permission to notify
(Android 13's POST_NOTIFICATIONS, iOS' and macOS' alert) was asked only
where a task's sheet chose its first reminder, so reminders typed in quick
add, added by the automatic reminder or brought by sync were scheduled and
dropped by the system without a word.

Now NotificationAccess, the device's, reads whether notifications are
allowed whenever the plan holds a reminder and asks where they aren't,
once an app start, so that a refusal isn't met with the dialog again and
again; the task sheet asks through it. While reminders are planned and
notifications are off, Settings' Reminders say so, with Turn on: asked
again, and where that doesn't allow it, the system's notification settings
of the app opened (flutter_local_notifications' own call, nothing added).
Read again whenever the app comes back.

Whats-New: Todo asks to notify as soon as there is a reminder, and Settings › Reminders shows when notifications are off, with Turn on.
Whats-New-De: Todo fragt nach Benachrichtigungen, sobald es eine Erinnerung gibt, und Einstellungen › Erinnerungen zeigt, wenn sie aus sind, mit Einschalten.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/lib/l10n/app_de.arb

@@ -254,6 +254,9 @@
   "snoozeTitle": "Schlummern für",
   "snoozeMinutes": "{count, plural, =1{1 Minute} other{{count} Minuten}}",
   "reminderSnooze": "{count} Min. schlummern",
+  "notificationsOffTitle": "Benachrichtigungen sind aus",
+  "notificationsOffHint": "Erinnerungen erscheinen erst, wenn Halkyon Todo dich benachrichtigen darf.",
+  "notificationsTurnOn": "Einschalten",
   "monthMore": "{count} weitere",
   "dayHeadingPattern": "EEEE, d. MMM",
   "overdueHide": "Überfälliges ausblenden",

apps/todo/halkyon_todo_flutter/lib/l10n/app_en.arb

@@ -812,6 +812,18 @@
       }
     }
   },
+  "notificationsOffTitle": "Notifications are off",
+  "@notificationsOffTitle": {
+    "description": "Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31)."
+  },
+  "notificationsOffHint": "Reminders can't show until Halkyon Todo may notify you.",
+  "@notificationsOffHint": {
+    "description": "Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31)."
+  },
+  "notificationsTurnOn": "Turn on",
+  "@notificationsTurnOn": {
+    "description": "Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31)."
+  },
   "monthMore": "{count} more",
   "@monthMore": {
     "description": "A project's Calendar as a month on wide windows (ADR 0033, D17): a day's tasks that don't fit.",

apps/todo/halkyon_todo_flutter/lib/l10n/app_localizations.dart

@@ -1624,6 +1624,24 @@ abstract class AppLocalizations {
   /// **'Snooze {count} min'**
   String reminderSnooze(int count);
 
+  /// Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31).
+  ///
+  /// In en, this message translates to:
+  /// **'Notifications are off'**
+  String get notificationsOffTitle;
+
+  /// Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31).
+  ///
+  /// In en, this message translates to:
+  /// **'Reminders can\'t show until Halkyon Todo may notify you.'**
+  String get notificationsOffHint;
+
+  /// Settings' Reminders while notifications are off and reminders are planned (ADR 0033, D31).
+  ///
+  /// In en, this message translates to:
+  /// **'Turn on'**
+  String get notificationsTurnOn;
+
   /// A project's Calendar as a month on wide windows (ADR 0033, D17): a day's tasks that don't fit.
   ///
   /// In en, this message translates to:

apps/todo/halkyon_todo_flutter/lib/l10n/app_localizations_de.dart

@@ -1006,6 +1006,16 @@ class AppLocalizationsDe extends AppLocalizations {
     return '$count Min. schlummern';
   }
 
+  @override
+  String get notificationsOffTitle => 'Benachrichtigungen sind aus';
+
+  @override
+  String get notificationsOffHint =>
+      'Erinnerungen erscheinen erst, wenn Halkyon Todo dich benachrichtigen darf.';
+
+  @override
+  String get notificationsTurnOn => 'Einschalten';
+
   @override
   String monthMore(int count) {
     return '$count weitere';

apps/todo/halkyon_todo_flutter/lib/l10n/app_localizations_en.dart

@@ -1006,6 +1006,16 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Snooze $count min';
   }
 
+  @override
+  String get notificationsOffTitle => 'Notifications are off';
+
+  @override
+  String get notificationsOffHint =>
+      'Reminders can\'t show until Halkyon Todo may notify you.';
+
+  @override
+  String get notificationsTurnOn => 'Turn on';
+
   @override
   String monthMore(int count) {
     return '$count more';