Fix E2E test gaps and add comprehensive E2E + parity test suites

- Fix pull consumer fetch: send original stream subject in HMSG (not inbox)
  so NATS client distinguishes data messages from control messages
- Fix MaxAge expiry: add background timer in StreamManager for periodic pruning
- Fix JetStream wire format: Go-compatible anonymous objects with string enums,
  proper offset-based pagination for stream/consumer list APIs
- Add 42 E2E black-box tests (core messaging, auth, TLS, accounts, JetStream)
- Add ~1000 parity tests across all subsystems (gaps closure)
- Update gap inventory docs to reflect implementation status

src/NATS.Server/JetStream/Storage/FileStore.cs

@@ -774,11 +774,7 @@ public sealed class FileStore : IStreamStore, IAsyncDisposable, IDisposable
     {
         if (string.IsNullOrEmpty(filter))
             return true;
-
-        if (NATS.Server.Subscriptions.SubjectMatch.IsLiteral(filter))
-            return string.Equals(subject, filter, StringComparison.Ordinal);
-
-        return NATS.Server.Subscriptions.SubjectMatch.MatchLiteral(subject, filter);
+        return NATS.Server.Subscriptions.SubjectMatch.SubjectMatchesFilter(subject, filter);
     }
 
     /// <summary>