fix(session): acknowledge login after first placement

ACE intentionally creates the local player Hidden and releases that materialization state on LoginComplete. Sending LoginComplete from raw F746 receipt raced canonical placement and left the login haze visible. Route one one-shot completion callback from Runtime's local first-entry terminal edge to graphical and prepared headless hosts; retain a guarded accepted-Create edge only for content-less headless sessions. Focused Runtime login tests, all 79 Headless tests, the connected user gate, and the Release build pass.

src/AcDream.Runtime/Session/RuntimeFirstEntryDriveController.cs

@@ -61,6 +61,7 @@ internal sealed class RuntimeFirstEntryDriveController
     private bool _driving;
     /// <summary>C3c-R1 review F6: see <see cref="AttachRoute"/>.</summary>
     private object? _routeOwner;
+    private Action<RuntimeEntityRecord>? _localPlayerCompleted;
 
     internal RuntimeFirstEntryDriveController(
         RuntimeEntityObjectLifetime entityObjects,
@@ -155,7 +156,9 @@ internal sealed class RuntimeFirstEntryDriveController
     /// before the prior route detached would otherwise let the OLD route's
     /// dispose wipe the NEW route's tracked entries.
     /// </summary>
-    internal void AttachRoute(object route)
+    internal void AttachRoute(
+        object route,
+        Action<RuntimeEntityRecord>? localPlayerCompleted = null)
     {
         ArgumentNullException.ThrowIfNull(route);
         if (_routeOwner is not null && !ReferenceEquals(_routeOwner, route))
@@ -166,6 +169,7 @@ internal sealed class RuntimeFirstEntryDriveController
                 + "precedes a new route) before a replacement attaches.");
         }
         _routeOwner = route;
+        _localPlayerCompleted = localPlayerCompleted;
     }
 
     /// <summary>
@@ -181,6 +185,7 @@ internal sealed class RuntimeFirstEntryDriveController
         if (!ReferenceEquals(_routeOwner, route))
             return;
         _routeOwner = null;
+        _localPlayerCompleted = null;
         _pending.Clear();
     }
 
@@ -198,6 +203,7 @@ internal sealed class RuntimeFirstEntryDriveController
 
             bool terminal;
             bool awaitingContinuationPlacement;
+            bool localPlayerCompleted = false;
             if (pending.IsLocalPlayer)
             {
                 RuntimeLocalPlayerFirstEntryStatus status =
@@ -214,6 +220,8 @@ internal sealed class RuntimeFirstEntryDriveController
                     is RuntimeLocalPlayerFirstEntryStatus.Completed
                     or RuntimeLocalPlayerFirstEntryStatus.RejectedToken
                     or RuntimeLocalPlayerFirstEntryStatus.RejectedAuthority;
+                localPlayerCompleted = status
+                    is RuntimeLocalPlayerFirstEntryStatus.Completed;
                 awaitingContinuationPlacement = status
                     is RuntimeLocalPlayerFirstEntryStatus
                         .AwaitingContinuationPlacement;
@@ -241,6 +249,8 @@ internal sealed class RuntimeFirstEntryDriveController
             if (terminal)
             {
                 _pending.Remove(key);
+                if (localPlayerCompleted)
+                    _localPlayerCompleted?.Invoke(pending.Record);
                 return;
             }
             if (!awaitingContinuationPlacement)