Make remote localization startup non-blocking

src/__Libraries/StellaOps.Localization/TranslationRegistry.cs

@@ -44,28 +44,28 @@ public sealed class TranslationRegistry
         // Ensure default locale is always loaded
         allLocales.Add(_options.DefaultLocale);
 
-        // Load bundles in priority order (lower first, higher overwrites)
+        // Load bundles in priority order (lower first, higher overwrites).
+        // Locales within the same provider are independent, so load them concurrently
+        // and merge back in deterministic locale order.
         foreach (var provider in ordered)
         {
-            foreach (var locale in allLocales)
+            var loadTasks = allLocales
+                .OrderBy(locale => locale, StringComparer.OrdinalIgnoreCase)
+                .Select(locale => LoadProviderBundleAsync(provider, locale, ct))
+                .ToArray();
+
+            var results = await Task.WhenAll(loadTasks).ConfigureAwait(false);
+            foreach (var result in results)
             {
-                try
+                if (result.Bundle.Count == 0)
                 {
-                    var bundle = await provider.LoadAsync(locale, ct).ConfigureAwait(false);
-                    if (bundle.Count > 0)
-                    {
-                        MergeBundles(locale, bundle);
-                        _logger.LogDebug(
-                            "Loaded {Count} translations for locale {Locale} from provider (priority {Priority})",
-                            bundle.Count, locale, provider.Priority);
-                    }
-                }
-                catch (Exception ex)
-                {
-                    _logger.LogWarning(ex,
-                        "Failed to load translations for locale {Locale} from provider (priority {Priority})",
-                        locale, provider.Priority);
+                    continue;
                 }
+
+                MergeBundles(result.Locale, result.Bundle);
+                _logger.LogDebug(
+                    "Loaded {Count} translations for locale {Locale} from provider (priority {Priority})",
+                    result.Bundle.Count, result.Locale, provider.Priority);
             }
         }
 
@@ -75,6 +75,27 @@ public sealed class TranslationRegistry
             _store.Count, totalKeys);
     }
 
+    private async Task<ProviderLocaleBundle> LoadProviderBundleAsync(
+        ITranslationBundleProvider provider,
+        string locale,
+        CancellationToken ct)
+    {
+        try
+        {
+            var bundle = await provider.LoadAsync(locale, ct).ConfigureAwait(false);
+            return new ProviderLocaleBundle(locale, bundle);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to load translations for locale {Locale} from provider (priority {Priority})",
+                locale, provider.Priority);
+            return new ProviderLocaleBundle(
+                locale,
+                new Dictionary<string, string>(StringComparer.Ordinal));
+        }
+    }
+
     /// <summary>
     /// Merges a bundle into the store. Higher-priority values overwrite lower.
     /// </summary>
@@ -248,4 +269,6 @@ public sealed class TranslationRegistry
             _ => value.ToString() ?? string.Empty
         };
     }
+
+    private sealed record ProviderLocaleBundle(string Locale, IReadOnlyDictionary<string, string> Bundle);
 }