Add initial configuration, tokens, and widgets for M3E components

- Introduced `.gitignore` and `.metadata` for apps and examples.
- Added Flutter/Dart analysis configurations (`analysis_options.yaml`).
- Implemented foundational tokens and themes for M3E (colors, shapes).
- Created base implementations for `IconButtonM3E` and `SplitButtonM3E`.
- Set up CI workflow (`ci.yaml`) to automate testing and analysis.

tool/create_component.dart

@@ -0,0 +1,172 @@
+import 'dart:io';
+
+String _pascal(String s) => s
+    .split('_')
+    .map((p) => p.isEmpty ? '' : (p[0].toUpperCase() + p.substring(1)))
+    .join();
+
+void _ensureCollectionExport(String pkg) {
+  final path = 'packages/m3e_collection/lib/m3e_collection.dart';
+  final file = File(path);
+  if (!file.existsSync()) return;
+  final content = file.readAsStringSync();
+  final exportLine = "export 'package:$pkg/$pkg.dart';";
+  if (content.contains(exportLine)) return;
+
+  // Append the export line at the end, preserving a trailing newline.
+  final updated = content.trimRight() + '\n' + exportLine + '\n';
+  file.writeAsStringSync(updated);
+}
+
+void _ensureCollectionDependency(String pkg) {
+  final path = 'packages/m3e_collection/pubspec.yaml';
+  final file = File(path);
+  if (!file.existsSync()) return;
+  final content = file.readAsStringSync();
+
+  // If dependency already present, skip.
+  final keyPattern =
+      RegExp(r'^\s*' + RegExp.escape(pkg) + r'\s*:', multiLine: true);
+  if (keyPattern.hasMatch(content)) return;
+
+  // Ensure we are within dependencies block. If the file contains a dependencies: section,
+  // we can safely append additional two-space indented entries at EOF since there is no
+  // subsequent top-level section in the current file structure.
+  if (!content.contains(RegExp(r'^dependencies:\s*$', multiLine: true))) {
+    stderr.writeln(
+        'Warning: packages/m3e_collection/pubspec.yaml has no dependencies section; skipping adding $pkg.');
+    return;
+  }
+
+  final addition = '  $pkg:\n    path: ../$pkg\n';
+  final updated = content.trimRight() + '\n' + addition + '\n';
+  file.writeAsStringSync(updated);
+}
+
+void _ensureCollectionOverride(String pkg) {
+  final path = 'packages/m3e_collection/pubspec_overrides.yaml';
+  final file = File(path);
+  if (!file.existsSync()) return;
+  var content = file.readAsStringSync();
+
+  // If override already present, skip.
+  final keyPattern =
+      RegExp(r'^\s*' + RegExp.escape(pkg) + r'\s*:', multiLine: true);
+  if (keyPattern.hasMatch(content)) return;
+
+  // Update the melos managed header list if present.
+  final headerRe = RegExp(r'^(#\s*melos_managed_dependency_overrides:\s*)(.*)$',
+      multiLine: true);
+  content = content.replaceFirstMapped(headerRe, (m) {
+    final prefix = m.group(1)!;
+    final list = m.group(2)!.trim();
+    if (list.isEmpty) return '${prefix}$pkg';
+    final items = list.split(',').map((s) => s.trim()).toList();
+    if (!items.contains(pkg)) {
+      items.add(pkg);
+    }
+    return prefix + items.join(',');
+  });
+
+  // Ensure dependency_overrides: section exists; if not, create it.
+  if (!content
+      .contains(RegExp(r'^dependency_overrides:\s*$', multiLine: true))) {
+    if (!content.endsWith('\n')) content += '\n';
+    content += 'dependency_overrides:\n';
+  }
+
+  // Append our override using Windows-style path to match existing file style.
+  final addition = '  $pkg:\n    path: ..\\$pkg\n';
+  content = content.trimRight() + '\n' + addition + '\n';
+  file.writeAsStringSync(content);
+}
+
+void main(List<String> args) async {
+  final nameArg =
+      args.firstWhere((a) => a.startsWith('name='), orElse: () => 'name=');
+  final name = nameArg.split('=').last;
+  if (name.isEmpty) {
+    stderr.writeln(
+        'Usage: melos run create -- name=<component> (_m3e suffix added automatically)');
+    exit(64);
+  }
+  final pkg = '${name}_m3e';
+  final dir = Directory('packages/$pkg');
+  if (dir.existsSync()) {
+    stderr.writeln('Package $pkg already exists.');
+    exit(1);
+  }
+  dir.createSync(recursive: true);
+
+  File('packages/$pkg/pubspec.yaml').writeAsStringSync('''
+name: $pkg
+description: $name (Material 3 Expressive)
+version: 0.1.0
+publish_to: none
+
+environment:
+  sdk: ">=3.5.0 <4.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  m3e_design:
+    path: ../m3e_design
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+''');
+
+  Directory('packages/$pkg/lib').createSync();
+  File('packages/$pkg/lib/$pkg.dart').writeAsStringSync('''
+library $pkg;
+
+// TODO: implement $name M3E widget
+export 'src/${name}_m3e_widget.dart';
+''');
+
+  Directory('packages/$pkg/lib/src').createSync();
+  File('packages/$pkg/lib/src/${name}_m3e_widget.dart').writeAsStringSync('''
+import 'package:flutter/material.dart';
+import 'package:m3e_design/m3e_design.dart';
+
+class ${_pascal(name)}M3EWidget extends StatelessWidget {
+  const ${_pascal(name)}M3EWidget({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final m3e = context.m3e;
+    return Container(
+      padding: EdgeInsets.all(m3e.spacing.md),
+      decoration: BoxDecoration(
+        color: m3e.colors.surfaceStrong,
+        borderRadius: m3e.shapes.square.md,
+      ),
+      child: Text('${_pascal(name)} placeholder', style: m3e.typography.base.titleMedium),
+    );
+  }
+}
+
+String _pascal(String s) => s.split('_').map((p) => p.isEmpty ? '' : (p[0].toUpperCase() + p.substring(1))).join();
+''');
+
+  Directory('packages/$pkg/test').createSync();
+  File('packages/$pkg/test/${name}_m3e_test.dart').writeAsStringSync('''
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('placeholder', () {
+    expect(1 + 1, 2);
+  });
+}
+''');
+
+  // Also add this new package to the aggregated collection package.
+  _ensureCollectionExport(pkg);
+  _ensureCollectionDependency(pkg);
+  _ensureCollectionOverride(pkg);
+
+  stdout.writeln(
+      'Created packages/$pkg and updated m3e_collection to include it.');
+}