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

tests/NATS.Server.Tests/WebSocket/WebSocketOptionsTests.cs

@@ -1,4 +1,5 @@
 using Shouldly;
+using NATS.Server.WebSocket;
 
 namespace NATS.Server.Tests.WebSocket;
 
@@ -23,4 +24,27 @@ public class WebSocketOptionsTests
         opts.WebSocket.ShouldNotBeNull();
         opts.WebSocket.Port.ShouldBe(-1);
     }
+
+    [Fact]
+    public void WsAuthConfig_sets_auth_override_when_websocket_auth_fields_are_present()
+    {
+        var ws = new WebSocketOptions
+        {
+            Username = "u",
+        };
+
+        WsAuthConfig.Apply(ws);
+
+        ws.AuthOverride.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void WsAuthConfig_keeps_auth_override_false_when_no_ws_auth_fields_are_present()
+    {
+        var ws = new WebSocketOptions();
+
+        WsAuthConfig.Apply(ws);
+
+        ws.AuthOverride.ShouldBeFalse();
+    }
 }