feat: replace mail protocol with smolmail and rebuild the UI

lib/shared/configs/flash_mail_icons.dart

@@ -1,17 +1,17 @@
 // ignore_for_file: constant_identifier_names
-///
-/// Flutter icons FlashMailIcons
-/// Copyright (C) 2023 by original authors @ fluttericon.com, fontello.com
-/// This font was generated by FlutterIcon.com, which is derived from Fontello.
-///
-/// To use this font, place it in your fonts/ directory and include the
-/// following in your pubspec.yaml
-///
-/// flutter:
-///   fonts:
-///    - family:  FlashMailIcons
-///      fonts:
-///       - asset: fonts/FlashMailIcons.ttf
+//
+// Flutter icons FlashMailIcons
+// Copyright (C) 2023 by original authors @ fluttericon.com, fontello.com
+// This font was generated by FlutterIcon.com, which is derived from Fontello.
+//
+// To use this font, place it in your fonts/ directory and include the
+// following in your pubspec.yaml
+//
+// flutter:
+//   fonts:
+//    - family:  FlashMailIcons
+//      fonts:
+//       - asset: fonts/FlashMailIcons.ttf
 
 import "package:flutter/widgets.dart";
 

lib/shared/utils/avatar_color.dart

@@ -0,0 +1,15 @@
+import "package:flutter/material.dart";
+
+/// A deterministic color for [key] (e.g. a contact address), picked from
+/// [palette] — same contact always gets the same avatar color, and every
+/// choice comes from the app's own palette instead of arbitrary RGB space.
+Color colorForKey(String key, List<Color> palette) {
+  if (palette.isEmpty) return Colors.grey;
+  final hash = key.codeUnits.fold<int>(0, (acc, c) => (acc * 31 + c) & 0x7fffffff);
+  return palette[hash % palette.length];
+}
+
+/// Black or white, whichever reads clearly on [background].
+Color contrastingTextColor(Color background) {
+  return background.computeLuminance() > 0.5 ? Colors.black : Colors.white;
+}

lib/shared/utils/format.dart

@@ -0,0 +1,37 @@
+import "package:flutter/material.dart";
+import "package:flutter/services.dart";
+import "package:intl/intl.dart";
+
+/// One path for all replies so the Re: rule lives once.
+String replySubject(String subject) =>
+    subject.isEmpty || subject.startsWith("Re:") ? subject : "Re: $subject";
+
+String formatTime(int? seconds) {
+  if (seconds == null) return "";
+  final date = DateTime.fromMillisecondsSinceEpoch(seconds * 1000, isUtc: true);
+  return DateFormat.yMMMMd().add_jm().format(date.toLocal());
+}
+
+/// The full date is too wide for a list row's trailing slot — this is what
+/// message_tile.dart shows instead: just a time for today, else a short date.
+String formatShortTime(int? seconds) {
+  if (seconds == null) return "";
+  final date =
+      DateTime.fromMillisecondsSinceEpoch(seconds * 1000, isUtc: true).toLocal();
+  final now = DateTime.now();
+  if (date.year == now.year && date.month == now.month && date.day == now.day) {
+    return DateFormat.jm().format(date);
+  }
+  if (date.year == now.year) {
+    return DateFormat.MMMd().format(date);
+  }
+  return DateFormat.yMd().format(date);
+}
+
+Future<void> copyText(BuildContext context, String text) async {
+  await Clipboard.setData(ClipboardData(text: text));
+  if (context.mounted) {
+    ScaffoldMessenger.of(context)
+        .showSnackBar(const SnackBar(content: Text("Copied to clipboard")));
+  }
+}

lib/shared/utils/random_color.dart

@@ -1,12 +0,0 @@
-import "dart:math";
-import "dart:ui";
-
-Color getRandomColor() {
-  Random random = Random();
-  return Color.fromRGBO(
-    random.nextInt(256),
-    random.nextInt(256),
-    random.nextInt(256),
-    1,
-  );
-}

lib/shared/utils/random_string.dart

@@ -1,12 +0,0 @@
-import "dart:math";
-
-String randomString(int length) {
-  const charset =
-      "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-  final random = Random.secure();
-  final codeUnits = List<int>.generate(
-    length,
-    (index) => charset.codeUnitAt(random.nextInt(charset.length)),
-  );
-  return String.fromCharCodes(codeUnits);
-}

lib/shared/utils/regex_patterns.dart

@@ -1,3 +0,0 @@
-final RegExp emailRegex = RegExp(
-  r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$',
-);

lib/shared/utils/snackbar.dart

@@ -0,0 +1,15 @@
+import "package:flutter/material.dart";
+
+/// Errors get the error color explicitly — the theme's default SnackBar is
+/// neutral, so a plain SnackBar(content: ...) is *not* red anymore.
+void showErrorSnackBar(BuildContext context, String message,
+    {Duration? duration}) {
+  final scheme = Theme.of(context).colorScheme;
+  ScaffoldMessenger.of(context).showSnackBar(
+    SnackBar(
+      backgroundColor: scheme.error,
+      duration: duration ?? const Duration(seconds: 4),
+      content: Text(message, style: TextStyle(color: scheme.onError)),
+    ),
+  );
+}