chore: Initial commit

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XPovRHpejR4zRxuhjY4Qs3

lib/utils/avatar_label_helper.dart

@@ -0,0 +1,39 @@
+class AvatarLabelHelper {
+  static final RegExp _alnumChunks = RegExp(r'[A-Za-z0-9]+');
+
+  static String buildLabel(String name) {
+    final trimmed = name.trim();
+    if (trimmed.isEmpty) return '?';
+
+    if (trimmed.startsWith('#')) {
+      final hashBody = trimmed.substring(1).replaceAll(RegExp(r'[\s_-]+'), '');
+      if (hashBody.isEmpty) {
+        return '#';
+      }
+      return '#${_take(hashBody, 2)}'.toUpperCase();
+    }
+
+    final parts = _alnumChunks
+        .allMatches(trimmed)
+        .map((match) => match.group(0)!)
+        .where((part) => part.isNotEmpty)
+        .toList();
+
+    if (parts.isEmpty) {
+      return '?';
+    }
+
+    if (parts.length >= 2) {
+      final first = _take(parts[0], 1);
+      final second = _take(parts[1], 1);
+      return '$first$second'.toUpperCase();
+    }
+
+    return _take(parts.first, 2).toUpperCase();
+  }
+
+  static String _take(String value, int count) {
+    if (value.length <= count) return value;
+    return value.substring(0, count);
+  }
+}