fix(render): harden portal exit handoff

src/AcDream.App/Rendering/RenderFrameDiagnosticsController.cs

@@ -128,9 +128,10 @@ internal readonly record struct ProcessResourceDiagnostics(
     int TrackedGpuTextures);
 
 /// <summary>
-/// Immutable resource facts captured only when explicit UI-probe dumping is enabled.
-/// Grouping keeps the diagnostics controller independent from every canonical renderer,
-/// VFX, mesh, texture, and process owner used to produce the values.
+/// Immutable resource facts captured only by an explicit low-frequency
+/// diagnostic such as UI-probe dumping or reveal timing. Grouping keeps the
+/// consumers independent from every canonical renderer, VFX, mesh, texture,
+/// and process owner used to produce the values.
 /// </summary>
 internal readonly record struct RenderFrameResourceDiagnosticsSnapshot(
     VfxStreamResourceDiagnostics Vfx,