chore(infra): update compose configurations, mqtt health bridge, and export scripts

FinlyticBackend/Util/BackendMqttBridge.cs

@@ -9,6 +9,7 @@ using FinlyticBackend.Database;
 using FinlyticBackend.Hubs;
 using FinlyticBackend.Services;
 using FinlyticBackend.Settings;
+using FinlyticCore.Dtos;
 using FinlyticCore.Dtos.Bot;
 using FinlyticCore.Dtos.Logging;
 using FinlyticCore.Dtos.News;
@@ -104,6 +105,11 @@ public class BackendMqttBridge : ManagedMqttClient, IHostedService
             MqttTopics.RequestFilter(MqttTopics.Channels.BackendGetAggregatedFavorites),
             HandleGetAggregatedFavoritesRpcAsync);
 
+        // Username lookup RPC Endpoint for FinlyticNotify
+        await SubscribeRpcAsync<UserIdRequest, string?>(
+            MqttTopics.RequestFilter(MqttTopics.Channels.BackendGetUsername),
+            HandleGetUsernameRpcAsync);
+
         // FinlyticBackend previously never broadcast its OWN structured logs at all (it only relayed other
         // services' logs received on MqttTopics.LogsWildcard, subscribed above) - it never used
         // IFinlyticLogger<T>, so FinlyticLogBroadcaster.Broadcast was never invoked for anything happening
@@ -286,4 +292,24 @@ public class BackendMqttBridge : ManagedMqttClient, IHostedService
             "[BackendMqttBridge] Responded to backend_GetAggregatedFavorites with {Count} unique ISINs. [CorrelationId: {CorrelationId}]", isins.Count, correlationId);
         return isins;
     }
+
+    private async Task<string?> HandleGetUsernameRpcAsync(UserIdRequest? req, string correlationId)
+    {
+        if (req == null || req.UserId == Guid.Empty) return null;
+
+        using var scope = _scopeFactory.CreateScope();
+        var dbContext = scope.ServiceProvider.GetRequiredService<BackendDbContext>();
+
+        var user = await dbContext.Users
+            .AsNoTracking()
+            .FirstOrDefaultAsync(u => u.Id == req.UserId);
+
+        if (user == null) return null;
+
+        string username = !string.IsNullOrWhiteSpace(user.FullName)
+            ? user.FullName.Trim().ToLowerInvariant().Replace(" ", "_")
+            : user.Email.Split('@')[0].Trim().ToLowerInvariant();
+
+        return username;
+    }
 }