feat: consolidate backend and docker-compose setup

test/login_screen_test.dart

@@ -0,0 +1,43 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:app_pfm_ocr_v2/features/auth/login_screen.dart';
+
+void main() {
+  testWidgets('LoginScreen validation tests', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const ProviderScope(
+        child: MaterialApp(
+          home: LoginScreen(),
+        ),
+      ),
+    );
+
+    // Find the login button
+    final loginButtonFinder = find.byType(ElevatedButton);
+    expect(loginButtonFinder, findsOneWidget);
+
+    // Tap login button with empty inputs
+    await tester.tap(loginButtonFinder);
+    await tester.pumpAndSettle();
+
+    // Verify inline validation error text is displayed
+    expect(find.text('Username/ID cannot be empty'), findsOneWidget);
+    expect(find.text('Password cannot be empty'), findsOneWidget);
+
+    // Enter a username, and a short password (e.g. 5 chars)
+    final textFormFields = find.byType(TextFormField);
+    expect(textFormFields, findsNWidgets(2));
+
+    await tester.enterText(textFormFields.first, 'admin');
+    await tester.enterText(textFormFields.last, '12345');
+    
+    // Tap the login button again
+    await tester.tap(loginButtonFinder);
+    await tester.pumpAndSettle();
+
+    // Verify username warning is gone, but password length warning appears
+    expect(find.text('Username/ID cannot be empty'), findsNothing);
+    expect(find.text('Password must be at least 6 characters'), findsOneWidget);
+  });
+}