chore: Initial commit

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

lib/models/contact_group.dart

@@ -0,0 +1,39 @@
+class SavedContactGroup {
+  final String id;
+  final String sectionKey;
+  final String label;
+  final String query;
+  final DateTime createdAt;
+  final List<String>? matchPrefixes;
+  final bool isAutoGroup;
+
+  const SavedContactGroup({
+    required this.id,
+    required this.sectionKey,
+    required this.label,
+    required this.query,
+    required this.createdAt,
+    this.matchPrefixes,
+    this.isAutoGroup = false,
+  });
+
+  SavedContactGroup copyWith({
+    String? id,
+    String? sectionKey,
+    String? label,
+    String? query,
+    DateTime? createdAt,
+    List<String>? matchPrefixes,
+    bool? isAutoGroup,
+  }) {
+    return SavedContactGroup(
+      id: id ?? this.id,
+      sectionKey: sectionKey ?? this.sectionKey,
+      label: label ?? this.label,
+      query: query ?? this.query,
+      createdAt: createdAt ?? this.createdAt,
+      matchPrefixes: matchPrefixes ?? this.matchPrefixes,
+      isAutoGroup: isAutoGroup ?? this.isAutoGroup,
+    );
+  }
+}