fix(ui): gate — no void frames around the login wormhole; vitals icons centered

The login tunnel now covers from the first world-facing frame (the
sky-void backdrop can never present pre-tunnel) and holds through an
atomic tunnel-to-world swap at reveal completion — the void is
structurally unreachable on both edges, pinned by frame-sequence tests
across WorldSceneRenderer/WorldRevealCoordinator/LocalPlayerTeleport-
Controller/RuntimeWorldTransitState. Vitals detail icons draw at their
authored centered offsets in both stacked and side-by-side layouts.
Implemented and live-probed by the fix agent; finalized by the lead
after the agent parked post-verification (gates re-run green:
App 5512/3, Runtime 1747/0).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/Rendering/LoginPresentationFrameProbe.cs

@@ -0,0 +1,95 @@
+using System;
+
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Diagnostic owner for the render-presentation probe family (CLAUDE.md Code
+/// Structure Rules §5 — one static class per subsystem, typed properties read
+/// from the environment once at startup, never per-call-site
+/// <c>GetEnvironmentVariable</c> reads).
+/// </summary>
+internal static class RenderPresentationDiagnostics
+{
+    /// <summary>
+    /// Enter-world gate round (2026-08-17): per-frame presentation
+    /// classification for the login wormhole edges. When set, every completed
+    /// render frame is classified by WHAT PRESENTED — <c>world</c> /
+    /// <c>tunnel</c> / <c>black</c> / <c>void</c> — and a <c>[login-frames]</c>
+    /// line is written on every classification transition. The gate contract
+    /// is retail's: the sequence over a login must contain NO <c>void</c>
+    /// entry on either edge (black → tunnel → world, each swap atomic).
+    /// Not a user setting; not in <c>RuntimeOptions</c>; not persisted.
+    /// </summary>
+    public static bool ProbeLoginFrames { get; } =
+        Environment.GetEnvironmentVariable("ACDREAM_PROBE_LOGIN_FRAMES") == "1";
+}
+
+/// <summary>
+/// The frame-level truth for the login wormhole gate: classifies each
+/// completed render frame from the same outcome facts the orchestrator
+/// publishes, plus the two raw presentation inputs (actual tunnel-scene
+/// visibility and the live waiting-for-login latch), and logs one line per
+/// TRANSITION so the exact frame sequence at both wormhole edges is
+/// auditable.
+///
+/// <list type="bullet">
+/// <item><description><c>world</c> — the normal world viewport drew
+/// (<see cref="WorldRenderFrameOutcome.NormalWorldDrawn"/>).</description></item>
+/// <item><description><c>tunnel</c> — the portal-space scene was visible and
+/// drew over the frame's opaque black.</description></item>
+/// <item><description><c>black</c> — the frame presented the portal-viewport
+/// black clear with NO tunnel scene (retail's empty pre-player SmartBox:
+/// the gameplay screen before CreatePlayer draws no world and no
+/// tunnel).</description></item>
+/// <item><description><c>void</c> — the world path ran but drew nothing
+/// (the sky-only "waiting for login" backdrop, or an unavailable world
+/// generation). Retail NEVER presents this during a login — any void entry
+/// in a login sequence is the gate defect.</description></item>
+/// </list>
+/// </summary>
+internal sealed class LoginPresentationFrameProbe : IRenderFramePostDiagnosticsPhase
+{
+    private readonly Func<bool> _tunnelSceneVisible;
+    private readonly IRenderLoginStateSource _login;
+    private readonly Action<string> _log;
+    private long _frame;
+    private double _elapsedSeconds;
+    private string? _lastClass;
+
+    public LoginPresentationFrameProbe(
+        Func<bool> tunnelSceneVisible,
+        IRenderLoginStateSource login,
+        Action<string> log)
+    {
+        _tunnelSceneVisible = tunnelSceneVisible
+            ?? throw new ArgumentNullException(nameof(tunnelSceneVisible));
+        _login = login ?? throw new ArgumentNullException(nameof(login));
+        _log = log ?? throw new ArgumentNullException(nameof(log));
+    }
+
+    public void Process(RenderFrameInput input, RenderFrameOutcome outcome)
+    {
+        _frame++;
+        _elapsedSeconds += input.DeltaSeconds;
+
+        bool world = outcome.World.NormalWorldDrawn;
+        bool tunnel = _tunnelSceneVisible();
+        bool cover = outcome.Presentation.PortalViewportDrawn;
+        bool waiting = _login.IsWaitingForLogin;
+
+        string presentClass =
+            world ? "world"
+            : tunnel ? "tunnel"
+            : cover ? "black"
+            : "void";
+
+        if (presentClass == _lastClass)
+            return;
+        _lastClass = presentClass;
+        _log(
+            $"[login-frames] frame={_frame} t={_elapsedSeconds:F3}s "
+            + $"present={presentClass} waiting={(waiting ? 1 : 0)} "
+            + $"cover={(cover ? 1 : 0)} tunnel={(tunnel ? 1 : 0)} "
+            + $"world={(world ? 1 : 0)}");
+    }
+}

src/AcDream.App/Rendering/RenderFrameResourceController.cs

@@ -136,13 +136,35 @@ internal sealed class LocalPlayerTeleportRenderStateSource
     : IRenderFramePortalStateSource
 {
     private readonly LocalPlayerTeleportController _teleport;
+    private readonly IRenderLoginStateSource _login;
 
-    public LocalPlayerTeleportRenderStateSource(LocalPlayerTeleportController teleport)
+    public LocalPlayerTeleportRenderStateSource(
+        LocalPlayerTeleportController teleport,
+        IRenderLoginStateSource login)
     {
         _teleport = teleport ?? throw new ArgumentNullException(nameof(teleport));
+        _login = login ?? throw new ArgumentNullException(nameof(login));
     }
 
-    public bool IsPortalViewportVisible => _teleport.IsPortalViewportVisible;
+    /// <summary>
+    /// The frame presents the portal-viewport shape (opaque black clear, no
+    /// world draw, retained UI on top) when the tunnel scene is visible OR
+    /// while a live login is still pre-world. The second arm is retail's
+    /// pre-player gameplay screen: after char-select Enter queues UI mode
+    /// 0x10000008 (<c>CM_Login::SendNotice_BeginEnterWorld @ 0x006AD810</c>
+    /// from <c>CPlayerSystem::LogOnCharacter @ 0x0055F890</c>), the SmartBox
+    /// has no player and draws NO world — the screen behind the UI is black
+    /// until <c>SmartBox::teleport_in_progress @ 0x00451C20</c> goes high at
+    /// CreatePlayer and <c>gmSmartBoxUI::UseTime @ 0x004D6EAB</c> begins the
+    /// tunnel in the same tick. The former sky-only "waiting for login"
+    /// backdrop had no retail counterpart and presented as the gate's
+    /// entry-edge VOID (2026-08-17). Both flags flip on the update thread
+    /// (the login activation tick flips ChaseModeEverEntered AND makes the
+    /// tunnel visible before the next render), so the black → tunnel → world
+    /// sequence swaps atomically per frame.
+    /// </summary>
+    public bool IsPortalViewportVisible =>
+        _teleport.IsPortalViewportVisible || _login.IsWaitingForLogin;
 
     public uint ActiveDestinationCell => _teleport.ActiveDestinationCell;
 }

src/AcDream.App/Rendering/WorldSceneRenderer.cs

@@ -159,11 +159,13 @@ internal sealed class WorldSceneRenderer : IWorldSceneFramePhase
                         _sky.DayFraction);
                 }
 
-                // Retail keeps the live sky during EnterWorld while suppressing
-                // terrain and object geometry until chase mode has engaged.
-                if (_login.IsWaitingForLogin)
-                    return CompleteSkippedWorld();
-
+                // The former sky-only "waiting for login" skip lived here.
+                // It is unreachable now: LocalPlayerTeleportRenderStateSource
+                // folds IsWaitingForLogin into PortalViewportVisible (retail's
+                // pre-player gameplay screen draws NO world — black, not sky),
+                // so the portal-visible return above already covers every
+                // waiting frame. One gate computes the frame's visibility;
+                // this phase only enforces it.
                 _passes.DrawFlatTerrain(in camera, roots.PlayerLandblockId);
                 terrainDrawn = true;
             }
@@ -291,16 +293,6 @@ internal sealed class WorldSceneRenderer : IWorldSceneFramePhase
                 diagnostic.VisibleLandblocks,
                 diagnostic.TotalLandblocks,
                 NormalWorldDrawn: true);
-
-            WorldRenderFrameOutcome CompleteSkippedWorld()
-            {
-                CompleteWorldFrame();
-                worldFrameStarted = false;
-                pviewFrameStarted = false;
-                _selection?.CompleteFrame();
-                selectionFrameStarted = false;
-                return default;
-            }
         }
         catch (Exception renderFailure)
         {