feat: Add metro transit, gadgets, shop, social apps, and traffic models checkpoint

Ananta.Server/Ananta.Network/RpcFrameDispatcher.cs

@@ -38,7 +38,21 @@ internal static class RpcFrameDispatcher
 
         if (frame.Mode == 0x09)
         {
-            await router.DispatchAsync(session, frame, cancellationToken);
+            // Last-resort containment: the router already catches handler/fallback errors,
+            // but anything that still escapes here must only cost this one frame — an
+            // exception propagating to the TCP loop closes the session (client: Reconnecting).
+            try
+            {
+                await router.DispatchAsync(session, frame, cancellationToken);
+            }
+            catch (OperationCanceledException)
+            {
+                throw;
+            }
+            catch (Exception ex)
+            {
+                session.Log.Error($"dispatch survived frame mode=0x{frame.Mode:X2} (session kept)", ex);
+            }
             return;
         }