auto-claude: subtask-2-1 - Create LoadingDialog component with static show()

lib/components/loading_dialog.dart

@@ -0,0 +1,81 @@
+import 'package:flutter/material.dart';
+
+/// A reusable loading dialog component with a spinner and message.
+///
+/// Use the static [show] method to display the dialog and [hide] to dismiss it.
+///
+/// Example:
+/// ```dart
+/// // Show loading dialog
+/// LoadingDialog.show(context, message: 'Loading...');
+///
+/// // Perform async operation
+/// await someAsyncOperation();
+///
+/// // Hide loading dialog
+/// LoadingDialog.hide(context);
+/// ```
+class LoadingDialog extends StatelessWidget {
+  final String message;
+
+  const LoadingDialog({
+    super.key,
+    required this.message,
+  });
+
+  /// Shows a loading dialog with the specified [message].
+  ///
+  /// The dialog is non-dismissible by tapping outside.
+  /// Use [hide] to dismiss the dialog when the operation completes.
+  static Future<void> show(
+    BuildContext context, {
+    required String message,
+  }) {
+    return showDialog<void>(
+      context: context,
+      barrierDismissible: false,
+      builder: (BuildContext dialogContext) {
+        return LoadingDialog(message: message);
+      },
+    );
+  }
+
+  /// Hides the currently displayed loading dialog.
+  ///
+  /// Should be called after showing a dialog with [show].
+  static void hide(BuildContext context) {
+    Navigator.of(context).pop();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+    final textTheme = Theme.of(context).textTheme;
+
+    return Center(
+      child: Card(
+        elevation: 4,
+        color: colorScheme.surface,
+        child: Padding(
+          padding: const EdgeInsets.all(24.0),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              CircularProgressIndicator(
+                color: colorScheme.primary,
+              ),
+              const SizedBox(height: 16),
+              Text(
+                message,
+                style: textTheme.bodyMedium?.copyWith(
+                  color: colorScheme.onSurface,
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}