fix(storage): enforce strict <=500KB upload guarantee for private bucket

- Harden compression pipeline with iterative quality + dimension reduction
- Throw explicit error if final output still exceeds 500KB bucket limit
- Keep 1080px cap while allowing progressive downscaling to fit constraints
- Update login screen branding comment to car64

lib/screens/login_screen.dart

@@ -4,7 +4,7 @@ import 'package:flutter/material.dart';
 import '../main.dart';
 import '../theme/app_colors.dart';
 
-/// Branded login screen matching the HW Collector Hub email style.
+/// Branded login screen matching the car64 style.
 class LoginScreen extends StatefulWidget {
   const LoginScreen({super.key});
 

lib/services/storage_service.dart

@@ -78,24 +78,30 @@ class StorageService {
       throw Exception('Invalid image file.');
     }
 
-    final resized = decoded.width > _maxWidth
+    img.Image working = decoded.width > _maxWidth
         ? img.copyResize(decoded, width: _maxWidth)
         : decoded;
 
     var quality = 85;
-    Uint8List out = Uint8List.fromList(img.encodeJpg(resized, quality: quality));
+    Uint8List out = Uint8List.fromList(img.encodeJpg(working, quality: quality));
 
+    // First pass: reduce JPEG quality.
     while (out.lengthInBytes > _maxImageBytes && quality > 35) {
-      quality -= 10;
-      out = Uint8List.fromList(img.encodeJpg(resized, quality: quality));
+      quality -= 5;
+      out = Uint8List.fromList(img.encodeJpg(working, quality: quality));
+    }
+
+    // Second pass: reduce dimensions progressively if still above the limit.
+    while (out.lengthInBytes > _maxImageBytes && working.width > 320) {
+      final nextWidth = (working.width * 0.85).round();
+      working = img.copyResize(working, width: nextWidth);
+      out = Uint8List.fromList(img.encodeJpg(working, quality: quality));
     }
 
     if (out.lengthInBytes > _maxImageBytes) {
-      final reduced = img.copyResize(
-        resized,
-        width: (resized.width * 0.8).round(),
+      throw Exception(
+        'Image is too large after compression (${out.lengthInBytes} bytes).',
       );
-      out = Uint8List.fromList(img.encodeJpg(reduced, quality: 45));
     }
 
     return out;