feat(ux): add distinct success/info/error top overlay message styles

lib/main.dart

@@ -54,20 +54,44 @@ final scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();
 OverlayEntry? _activeMessageOverlay;
 Timer? _activeMessageOverlayTimer;
 
+enum GlobalMessageType { info, success, error }
+
 /// Show a snackbar safely through the global key.
 void showGlobalSnackBar(String message, {bool isError = false}) {
-  _showGlobalMessageOverlay(message, isError: isError);
+  _showGlobalMessageOverlay(
+    message,
+    type: isError ? GlobalMessageType.error : GlobalMessageType.info,
+  );
 }
 
-void _showGlobalMessageOverlay(String message, {required bool isError}) {
+void showGlobalSuccess(String message) {
+  _showGlobalMessageOverlay(message, type: GlobalMessageType.success);
+}
+
+void showGlobalInfo(String message) {
+  _showGlobalMessageOverlay(message, type: GlobalMessageType.info);
+}
+
+void _showGlobalMessageOverlay(
+  String message, {
+  required GlobalMessageType type,
+}) {
   final overlay = navigatorKey.currentState?.overlay;
   if (overlay == null) return;
 
   _activeMessageOverlayTimer?.cancel();
   _activeMessageOverlay?.remove();
 
-  final backgroundColor = isError ? Colors.red : const Color(0xFF1F2937);
-  final leadingIcon = isError ? Icons.error_outline : Icons.info_outline;
+  final backgroundColor = switch (type) {
+    GlobalMessageType.error => Colors.red,
+    GlobalMessageType.success => Colors.green,
+    GlobalMessageType.info => const Color(0xFF1F2937),
+  };
+  final leadingIcon = switch (type) {
+    GlobalMessageType.error => Icons.error_outline,
+    GlobalMessageType.success => Icons.check_circle_outline,
+    GlobalMessageType.info => Icons.info_outline,
+  };
 
   _activeMessageOverlay = OverlayEntry(
     builder: (context) {
@@ -343,7 +367,7 @@ class _ResetPasswordDialogState extends State<_ResetPasswordDialog> {
       );
       if (!mounted) return;
       Navigator.of(context).pop();
-      showGlobalSnackBar('Password updated successfully!');
+      showGlobalSuccess('Password updated successfully!');
     } on AuthException catch (e) {
       if (!mounted) return;
       setState(() => _isSaving = false);

lib/screens/collections_screen.dart

@@ -212,7 +212,7 @@ class CollectionsScreenState extends State<CollectionsScreen>
         name: nameCtrl.text.trim(),
         description: descCtrl.text.trim(),
       );
-      showGlobalSnackBar('Collection created!');
+      showGlobalSuccess('Collection created!');
       _load();
     } catch (e) {
       showGlobalError(
@@ -258,7 +258,7 @@ class CollectionsScreenState extends State<CollectionsScreen>
     if (!mounted) return;
     setState(() => _activeCollectionId = collectionId);
     MainCollectionSync.notifyChanged();
-    showGlobalSnackBar('Main collection set for scanning.');
+    showGlobalInfo('Main collection set for scanning.');
   }
 
   @override

lib/screens/garage_screen.dart

@@ -913,7 +913,7 @@ class GarageScreenState extends State<GarageScreen> {
     );
     if (xFile == null) return;
 
-    showGlobalSnackBar('Uploading photo…');
+    showGlobalInfo('Uploading photo…');
 
     final oldPath = car['user_image_url'] as String?;
     String newPath;
@@ -937,7 +937,7 @@ class GarageScreenState extends State<GarageScreen> {
           .update({'user_image_url': newPath})
           .eq('id', car['id']);
 
-      showGlobalSnackBar('Photo updated!');
+      showGlobalSuccess('Photo updated!');
       if (sheetContext.mounted) Navigator.pop(sheetContext);
       _loadCars(reset: true); // refresh grid
     } catch (e) {
@@ -968,7 +968,7 @@ class GarageScreenState extends State<GarageScreen> {
           .update(updated)
           .eq('id', car['id']);
 
-      showGlobalSnackBar('Car updated!');
+      showGlobalSuccess('Car updated!');
       if (sheetContext.mounted) Navigator.pop(sheetContext);
       _loadCars(reset: true);
     } catch (e) {
@@ -992,7 +992,7 @@ class GarageScreenState extends State<GarageScreen> {
           .maybeSingle();
 
       if (existingVote != null) {
-        showGlobalSnackBar('You already confirmed this catalog entry.');
+        showGlobalInfo('You already confirmed this catalog entry.');
         return;
       }
 
@@ -1001,7 +1001,7 @@ class GarageScreenState extends State<GarageScreen> {
         'user_id': user.id,
       });
 
-      showGlobalSnackBar('Thanks! Your validation vote was recorded.');
+      showGlobalSuccess('Thanks! Your validation vote was recorded.');
       if (sheetContext.mounted) Navigator.pop(sheetContext);
       _loadCars(reset: true);
     } catch (e) {
@@ -1044,7 +1044,7 @@ class GarageScreenState extends State<GarageScreen> {
           .maybeSingle();
 
       if (existingOpen != null) {
-        showGlobalSnackBar('You already have an open report for this car.');
+        showGlobalInfo('You already have an open report for this car.');
         return;
       }
 
@@ -1056,7 +1056,7 @@ class GarageScreenState extends State<GarageScreen> {
         'note': payload.note,
       });
 
-      showGlobalSnackBar('Thanks for reporting. We will review this entry.');
+      showGlobalSuccess('Thanks for reporting. We will review this entry.');
     } catch (e) {
       showGlobalError(
         e,
@@ -1185,7 +1185,7 @@ class GarageScreenState extends State<GarageScreen> {
 
       if (!mounted) return;
       if (sheetContext.mounted) Navigator.pop(sheetContext);
-      showGlobalSnackBar(widget.isOwner
+        showGlobalSuccess(widget.isOwner
           ? '${car['hw_id']} moved to another collection.'
           : '${car['hw_id']} copied to another collection.');
       await _loadCars(reset: true);
@@ -1242,7 +1242,7 @@ class GarageScreenState extends State<GarageScreen> {
       if (sheetContext.mounted) {
         Navigator.pop(sheetContext); // close bottom sheet
       }
-      showGlobalSnackBar('${car['hw_id']} removed from your garage.');
+      showGlobalSuccess('${car['hw_id']} removed from your garage.');
       _loadCars(reset: true);
     } catch (e) {
       showGlobalError(

lib/screens/login_screen.dart

@@ -78,7 +78,7 @@ class _LoginScreenState extends State<LoginScreen>
         email,
         redirectTo: 'hwcollector://login/recovery',
       );
-      showGlobalSnackBar('Password reset email sent! Check your inbox.');
+      showGlobalSuccess('Password reset email sent! Check your inbox.');
     } on AuthException catch (e) {
       showGlobalSnackBar(e.message, isError: true);
     }

lib/screens/manage_collection_screen.dart

@@ -125,7 +125,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
           memberCount: _collection.memberCount,
         );
       });
-      showGlobalSnackBar('Collection renamed!');
+      showGlobalSuccess('Collection renamed!');
     } catch (e) {
       showGlobalError(
         e,
@@ -244,7 +244,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
         email: email,
         role: inviteRole,
       );
-      showGlobalSnackBar(
+      showGlobalSuccess(
         inviteRole == 'viewer' ? 'Viewer invited!' : 'Member invited!',
       );
       await _loadMembers();
@@ -286,7 +286,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
         collectionId: _collection.id,
         memberUserId: member.userId,
       );
-      showGlobalSnackBar('Member removed.');
+      showGlobalSuccess('Member removed.');
       await _loadMembers();
     } catch (e) {
       showGlobalError(
@@ -322,7 +322,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
 
     try {
       await CollectionService.leave(_collection.id);
-      showGlobalSnackBar('Left "${_collection.name}".');
+      showGlobalSuccess('Left "${_collection.name}".');
       if (mounted) Navigator.pop(context);
     } catch (e) {
       showGlobalError(
@@ -358,7 +358,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
 
     try {
       await CollectionService.delete(_collection.id);
-      showGlobalSnackBar('Collection deleted.');
+      showGlobalSuccess('Collection deleted.');
       if (mounted) Navigator.pop(context);
     } catch (e) {
       showGlobalError(

lib/screens/profile_screen.dart

@@ -208,7 +208,7 @@ class ProfileScreen extends StatelessWidget {
                   UserAttributes(password: pw),
                 );
                 if (context.mounted) Navigator.pop(context);
-                showGlobalSnackBar('Password updated!');
+                showGlobalSuccess('Password updated!');
               } on AuthException catch (e) {
                 showGlobalSnackBar(e.message, isError: true);
               }

lib/screens/scan_tab.dart

@@ -391,7 +391,7 @@ class ScanTabState extends State<ScanTab> {
           await _addToCollection(collection.id, hwId);
           await _ensureValidationVote(hwId);
           if (!mounted) return false;
-          showGlobalSnackBar('$hwId added to "${collection.name}"! 🎉');
+          showGlobalSuccess('$hwId added to "${collection.name}"! 🎉');
         }
       } else {
         final discovery = await showModalBottomSheet<_NewDiscoveryData>(
@@ -415,7 +415,7 @@ class ScanTabState extends State<ScanTab> {
           );
           await _addToCollection(collection.id, hwId, notes: discovery.notes);
           if (!mounted) return false;
-          showGlobalSnackBar('$hwId added to "${collection.name}"! 🎉');
+          showGlobalSuccess('$hwId added to "${collection.name}"! 🎉');
         }
       }
       return true;