fix #416 #415: the retail button state/media machine — roster hover highlight clears; probe wait verbs bind without an artifact dir

#416 (char-select roster highlight never cleared on hover-leave): three
decomp-grounded mechanisms replace the media-keyed _availableStates
approximation.
- UIElement_Button::UpdateState_ @0x00471CF0: the button machine commits
  ONLY states authored on the button's OWN ElementDesc (AccessStateDesc
  gate); unauthored requests no-op, preserving custom semantic states.
- UIElement::SetState @0x00464E70: an unauthored state id is coerced to
  state 0 (the unnamed base state) and committed — ported into
  UiDatElement.TrySetRetailState with the base-descriptor PassToChildren
  cascade arm.
- The SetState media rule @0x004651c0: a committed state replaces the
  playing media ONLY when its media array is non-empty. UiButton now keeps
  per-face-segment media states under that rule (segments model retail's
  PassToChildren children), and LayoutImporter records the raw MediaCount
  including the File=0 draw-nothing images the drawable filter drops —
  the roster bar children's base state is exactly such an image, and it is
  what clears the bar.
The row template truth (probe, installed DAT): the row authors EMPTY
Normal/rollover/Highlight descriptors with PassToChildren; the three bar
children author rollover/Highlight media, NO Normal state, and a File=0
base image. An empty-media Normal_pressed still never blanks a Normal-art
button (the media rule keeps the previous art — the exact behavior the
old gate approximated), and the Appearance spins' property-only Highlight
now genuinely commits: label recolors, arrow art lingers — the retail
split AP-222 approximated with a requested-keyed label hack, now retired.
Live-verified at char select: hover +alex shows the grey bar, moving off
clears it, the selected row keeps its amber bar.

#415 (probe wait world-* verbs dead): the filed snapshot-reset diagnosis
was wrong — the automation bridge simply never bound without
ACDREAM_AUTOMATION_ARTIFACT_DIR. A facts-only
WorldRevealFactsAutomationRuntime now binds whenever the retained UI
exists; checkpoint/screenshot verbs still require the artifact directory
and now report that instead of a generic timeout.

App tests 5568/3 skips, Runtime 1756/0, UI.Abstractions 926/0.

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

tests/AcDream.App.Tests/UI/Layout/PowerbarLayoutProbeTests.cs

@@ -164,6 +164,30 @@ public sealed class PowerbarLayoutProbeTests
         DumpElement(strings, root!, 0);
     }
 
+    /// <summary>2026-08-17 #416 (stuck character-select rollover): dump the
+    /// character-management roster row template (0x21000004/0x100003A5) —
+    /// which states it authors, which of them carry media, and the default
+    /// state — so the hover-leave fix binds the authored truth.</summary>
+    [Fact]
+    public void ProbeCharacterSelectRowTemplate()
+    {
+        if (Environment.GetEnvironmentVariable("ACDREAM_PROBE_POWERBAR") != "1")
+            return;
+
+        var datDir = Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR")
+            ?? Path.Combine(
+                Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
+                "Documents",
+                "Asheron's Call");
+        using var dats = new DatCollection(datDir, DatAccessType.Read);
+        var strings = new DatStringResolver(dats);
+
+        ElementInfo? row = LayoutImporter.ImportInfos(dats, 0x21000004u, 0x100003A5u);
+        Assert.NotNull(row);
+        Console.WriteLine("[pbprobe] === char-select roster row 0x21000004/0x100003A5 ===");
+        DumpElement(strings, row!, 0);
+    }
+
     private static ElementInfo? FindById(ElementInfo element, uint id)
     {
         if (element.Id == id) return element;
@@ -219,7 +243,8 @@ public sealed class PowerbarLayoutProbeTests
                         $"0x{pair.Key:X2}:{pair.Value.Kind}=0x{pair.Value.UnsignedValue:X}"));
             Console.WriteLine(
                 $"[pbprobe] {indent}  state 0x{stateId:X8} '{state.Name}'"
-                + $" passToChildren={state.PassToChildren}{text} props[{properties}]");
+                + $" passToChildren={state.PassToChildren} mediaCount={state.MediaCount}"
+                + $"{text} props[{properties}]");
         }
         foreach (ElementInfo child in e.Children)
             DumpElement(strings, child, depth + 1);