fix(ui): chat window retail parity — focus rails, authored captions, menu flick, drag-stable text

Four of the five owner-reported chat deltas (2026-08-24), each traced to
its retail mechanism:

1. Missing gold separator left of the input: the chat input authors two
   1px Type-3 rail CHILDREN (0x10000017 at X=0, 0x10000018
   right-anchored) whose only media is Normal_focussed (0x06004D67,
   live-DAT probed). UiField consumes its DAT children, so the rails
   were swallowed and never drawn. The factory now folds them into the
   field, which draws both while focused.

2. Button says "General", retail says "Gen": the talk button's short
   caption comes from per-target ID_Chat_ChatTargetMenu* strings
   (HandleSelection @0x004cd540, StringTable 0x23000001 via
   compute_str_hash — recovered from the raw binary after BN elided the
   ids into name-hash globals). Authored set: Chat/Tell/Fell/Pat/Mon/
   Vas/Alg/Gen/Trade/LFG/RP/Soc/Olt. Menu rows + squelch/tell specials
   resolve from the same table (ID_Chat_TellTo*); production resolves
   through DatStringResolver, fallbacks ARE the authored EoR English.
   ChatStringsLiveDatTests pins the whole set against the installed DAT.

3. Channel button stayed green while the popup was open: retail's
   pressed face is the momentary physical press ("flicks"); the OPEN
   state drives only the arrow-cap child's StateDesc swap
   (UIElement_Menu::UpdateState @0x0046cad0 writes attribute 0xe).
   UiMenu now keys the face on the press, not on IsOpen.

4. Window-title/button text "vibrates" while dragging windows:
   DrawStringDatPass snapped glyphs with MathF.Round — banker's
   rounding. A centered label with a constant .5 fraction alternates
   round-up/round-down across successive integers, double-stepping then
   sticking while the background glides. Half-up Floor(v+0.5) snaps
   every tie one way: uniform 1px steps in lock-step with sprites.

The fifth report (input row sticking out on window resize) did not
reproduce: a controller-bound fixture resize at 220/300/600px keeps the
whole input row inside the window (test added) — awaiting the owner's
exact gesture.

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

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

@@ -672,4 +672,66 @@ public class ChatLayoutConformanceTests
         scroll.SetExtents(contentHeight: 400, viewHeight: 50, preserveEnd: true);
         Assert.Equal(draggedPosition, scroll.ScrollY);
     }
+
+    /// <summary>
+    /// 2026-08-24 owner report: resizing the chat window let the text input
+    /// stick out past the window edge. The authored edge modes (input row
+    /// 0x10000013 L1/R1 = stretch, field 0x10000016 L1/R1 = stretch, Send
+    /// 0x10000019 L2/R1 = right-docked, menu button 0x10000014 L1/R2 =
+    /// left-docked) must keep the whole input row inside the window at every
+    /// size, narrower AND wider than the authored 410.
+    /// </summary>
+    [Theory]
+    [InlineData(300f, 100f)]
+    [InlineData(600f, 160f)]
+    [InlineData(220f, 80f)]
+    public void ResizingTheWindow_KeepsTheInputRowInsideIt(float width, float height)
+    {
+        var infos = FixtureLoader.LoadChatInfos();
+        ImportedLayout layout = LayoutImporter.Build(infos, NoTex, null);
+        // Bind the REAL controller — production geometry overrides included.
+        var controller = ChatWindowController.Bind(
+            infos, layout, new ChatVM(new ChatLog()), () => NullCommandBus.Instance,
+            new ChatWindowState(), null, null, NoTex);
+        Assert.NotNull(controller);
+        UiElement window = layout.FindElement(0x10000600u)!;
+        var root = new UiRoot { Width = 800f, Height = 600f };
+        root.AddChild(window);
+        ApplyLayoutPassLocal(window);
+
+        window.Width = width;
+        window.Height = height;
+        window.ResetAnchorCapture();
+        ApplyLayoutPassLocal(window);
+        ApplyLayoutPassLocal(window); // second frame — policies settle
+
+        UiElement inputBar = layout.FindElement(0x10000013u)!;
+        UiElement input = layout.FindElement(0x10000016u)!;
+        UiElement send = layout.FindElement(0x10000019u)!;
+        UiElement menuButton = layout.FindElement(0x10000014u)!;
+
+        Assert.True(inputBar.Left >= 0f && inputBar.Left + inputBar.Width <= width + 0.5f,
+            $"input bar [{inputBar.Left},{inputBar.Left + inputBar.Width}] escapes window width {width}");
+        float inputRight = inputBar.Left + input.Left + input.Width;
+        Assert.True(inputRight <= width + 0.5f,
+            $"input field right {inputRight} escapes window width {width}");
+        float sendRight = inputBar.Left + send.Left + send.Width;
+        Assert.True(sendRight <= width + 0.5f,
+            $"send right {sendRight} escapes window width {width}");
+        Assert.True(menuButton.Left >= 0f, "menu button escaped left");
+        // The field must stay BETWEEN the menu button and the send button.
+        Assert.True(input.Left >= menuButton.Left + menuButton.Width - 0.5f,
+            $"input {input.Left} overlaps menu button ending {menuButton.Left + menuButton.Width}");
+        Assert.True(input.Left + input.Width <= send.Left + 0.5f,
+            $"input ends {input.Left + input.Width} past send start {send.Left}");
+    }
+
+    private static void ApplyLayoutPassLocal(UiElement parent)
+    {
+        foreach (var child in parent.Children)
+        {
+            child.ApplyAnchor(parent.Width, parent.Height);
+            ApplyLayoutPassLocal(child);
+        }
+    }
 }