fix(studio): show real download error, not 'hub not reachable'

friendlyError now pattern-matches module-download failures ('download
failed: ...') and renders a clear, copyable headline + the URL/status
detail, instead of letting the gRPC-Unavailable default show the generic
'hub not reachable' banner. EN+DE l10n.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/data/friendly_error.dart

@@ -122,6 +122,19 @@ FriendlyError friendlyError(Object error, AppLocalizations l) {
 FriendlyError? _matchHubPattern(String detail, AppLocalizations l) {
   if (detail.isEmpty) return null;
 
+  // Module bundle download failed (bad / unhosted URL). The hub wraps
+  // these as "download failed: ..." and (older builds) mapped them to
+  // gRPC Unavailable — which the code-default would render as the
+  // misleading "hub not reachable". The hub is fine; show the real URL
+  // + status (carried in `detail`) under a clear headline.
+  if (detail.contains('download failed') || detail.contains('download error')) {
+    return FriendlyError(
+      headline: l.errModuleDownload,
+      detail: detail,
+      hint: l.errModuleDownloadHint,
+    );
+  }
+
   // Approval rejected: "step 'X' rejected by Y: reason"
   if (detail.contains('rejected by')) {
     return FriendlyError(

lib/l10n/app_de.arb

@@ -1,5 +1,7 @@
 {
   "@@locale": "de",
+  "errModuleDownload": "Modul-Download fehlgeschlagen",
+  "errModuleDownloadHint": "Die Bundle-URL des Moduls ist nicht erreichbar (Statuscode unten). Der Hub läuft — URL/Host korrigieren oder anderen Store wählen.",
   "guidedSetupTitle": "Setup-Assistent",
   "guidedSetupIntro": "Beantworte drei Fragen — Ch∆In stellt passende Konfiguration, Modul-Set und Start-Flow zusammen.",
   "guidedSetupScenario": "Szenario",

lib/l10n/app_en.arb

@@ -1,5 +1,7 @@
 {
   "@@locale": "en",
+  "errModuleDownload": "Module download failed",
+  "errModuleDownloadHint": "The module's bundle URL is unreachable (status code below). The hub is running fine — fix the URL/host or choose another store.",
   "guidedSetupTitle": "Setup assistant",
   "guidedSetupIntro": "Answer three questions and Ch∆In assembles a tailored config, module set and starter flow.",
   "guidedSetupScenario": "Scenario",

lib/l10n/app_localizations.dart

@@ -98,6 +98,18 @@ abstract class AppLocalizations {
     Locale('en'),
   ];
 
+  /// No description provided for @errModuleDownload.
+  ///
+  /// In en, this message translates to:
+  /// **'Module download failed'**
+  String get errModuleDownload;
+
+  /// No description provided for @errModuleDownloadHint.
+  ///
+  /// In en, this message translates to:
+  /// **'The module\'s bundle URL is unreachable (status code below). The hub is running fine — fix the URL/host or choose another store.'**
+  String get errModuleDownloadHint;
+
   /// No description provided for @guidedSetupTitle.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -8,6 +8,13 @@ import 'app_localizations.dart';
 class AppLocalizationsDe extends AppLocalizations {
   AppLocalizationsDe([String locale = 'de']) : super(locale);
 
+  @override
+  String get errModuleDownload => 'Modul-Download fehlgeschlagen';
+
+  @override
+  String get errModuleDownloadHint =>
+      'Die Bundle-URL des Moduls ist nicht erreichbar (Statuscode unten). Der Hub läuft — URL/Host korrigieren oder anderen Store wählen.';
+
   @override
   String get guidedSetupTitle => 'Setup-Assistent';
 

lib/l10n/app_localizations_en.dart

@@ -8,6 +8,13 @@ import 'app_localizations.dart';
 class AppLocalizationsEn extends AppLocalizations {
   AppLocalizationsEn([String locale = 'en']) : super(locale);
 
+  @override
+  String get errModuleDownload => 'Module download failed';
+
+  @override
+  String get errModuleDownloadHint =>
+      'The module\'s bundle URL is unreachable (status code below). The hub is running fine — fix the URL/host or choose another store.';
+
   @override
   String get guidedSetupTitle => 'Setup assistant';