feat(D.2b): UiMenu (Type 6) — generic dropdown; channel knowledge moves to controller (widget-generalization Task 4)

UiChannelMenu → UiMenu: removed ChatChannelKind, the 14-item array, the
button-text map, and the availability default. Generic surface: MenuItem
(label + object? Payload), Selected (object?), OnSelect, EnabledProvider,
ButtonLabelProvider, RowsPerColumn/RowHeight/ColumnWidth (all settable).
All draw/event mechanics unchanged — same popup geometry, same click
coordinates, same 8-piece bevel, same 3-slice button face.

ChatWindowController gains ChannelItems[], ChannelButtonLabel(), and
ChannelAvailable() (verbatim from old widget), and populates the
factory-built Type-6 UiMenu via find-by-id rather than constructing a
replacement widget. The Menu property type is now UiMenu. OnChannelChanged
wrap replaced with the generic OnSelect wrap for the ReflowInputRow hook.

DatWidgetFactory registers Type 6 → new UiMenu().

Tests: UiChannelMenuTests → UiMenuTests (10 tests, all green); factory
Type6 test added; ChatWindowControllerTests updated to use OnSelect.
Divergence register: AP-42 added (flat item model vs retail nested-submenu
MakePopup @0x46d310 — latent, unreachable through the chat menu).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/AcDream.App.Tests/UI/UiMenuTests.cs

@@ -0,0 +1,170 @@
+using System.Collections.Generic;
+using System.Linq;
+using AcDream.App.UI;
+using AcDream.UI.Abstractions;
+
+namespace AcDream.App.Tests.UI;
+
+public class UiMenuTests
+{
+    // PopupH = RowsPerColumn(7) * RowHeight(17) = 119; popup opens upward so top = -119.
+    // Item idx -> col = idx/7, row = idx%7; row band y in [top+row*17, top+(row+1)*17).
+    // Right column needs lx >= ColumnWidth(191) + Border(5) = lx >= 196 after bevel offset,
+    // but the original tests used lx=200 which maps ix=195 -> col=(int)(195/191)=1. OK.
+
+    // The 14 channel items verbatim (matches ChannelItems in ChatWindowController).
+    private static readonly UiMenu.MenuItem[] ChannelItems =
+    {
+        new("Squelch (ignore)",      (object?)null),
+        new("Tell to Selected",      (object?)null),
+        new("Chat to All",           (object?)ChatChannelKind.Say),
+        new("Tell to Fellows",       (object?)ChatChannelKind.Fellowship),
+        new("Tell to General Chat",  (object?)ChatChannelKind.General),
+        new("Tell to LFG Chat",      (object?)ChatChannelKind.Lfg),
+        new("Tell to Society Chat",  (object?)ChatChannelKind.Society),
+        new("Tell to Monarch",       (object?)ChatChannelKind.Monarch),
+        new("Tell to Patron",        (object?)ChatChannelKind.Patron),
+        new("Tell to Vassals",       (object?)ChatChannelKind.Vassals),
+        new("Tell to Allegiance",    (object?)ChatChannelKind.Allegiance),
+        new("Tell to Trade Chat",    (object?)ChatChannelKind.Trade),
+        new("Tell to Roleplay Chat", (object?)ChatChannelKind.Roleplay),
+        new("Tell to Olthoi Chat",   (object?)ChatChannelKind.Olthoi),
+    };
+
+    // Availability gate identical to ChatWindowController.ChannelAvailable.
+    private static bool ChannelAvailable(object? p)
+        => p is ChatChannelKind ch
+               ? ch is ChatChannelKind.Say or ChatChannelKind.General
+                      or ChatChannelKind.Trade or ChatChannelKind.Lfg
+               : false;   // null-payload (Squelch/Tell-to-Selected) = inert
+
+    private UiMenu MakeMenu() => new UiMenu
+    {
+        Width = 80f, Height = 18f,
+        Items = ChannelItems,
+        Selected = (object?)ChatChannelKind.Say,
+        EnabledProvider = ChannelAvailable,
+    };
+
+    [Fact]
+    public void Items_HasExpected14Entries()
+    {
+        Assert.Equal(14, ChannelItems.Length);
+    }
+
+    [Fact]
+    public void Items_FirstEntry_IsSquelch_Special()
+    {
+        Assert.Equal("Squelch (ignore)", ChannelItems[0].Label);
+        Assert.Null(ChannelItems[0].Payload);
+    }
+
+    [Fact]
+    public void Items_LastEntry_IsOlthoi()
+    {
+        var last = ChannelItems[^1];
+        Assert.Equal("Tell to Olthoi Chat", last.Label);
+        Assert.Equal(ChatChannelKind.Olthoi, last.Payload);
+    }
+
+    [Fact]
+    public void Items_ContainAll12ChannelKinds()
+    {
+        var kinds = new HashSet<ChatChannelKind>(
+            ChannelItems.Where(i => i.Payload is ChatChannelKind).Select(i => (ChatChannelKind)i.Payload!));
+        foreach (var k in new[]
+        {
+            ChatChannelKind.Say, ChatChannelKind.General, ChatChannelKind.Trade, ChatChannelKind.Lfg,
+            ChatChannelKind.Fellowship, ChatChannelKind.Allegiance, ChatChannelKind.Patron,
+            ChatChannelKind.Vassals, ChatChannelKind.Monarch, ChatChannelKind.Roleplay,
+            ChatChannelKind.Society, ChatChannelKind.Olthoi,
+        })
+            Assert.Contains(k, kinds);
+    }
+
+    [Fact]
+    public void DefaultSelected_IsNull_OnBlankMenu()
+    {
+        // A freshly constructed UiMenu has no Selected by default (controller sets it).
+        Assert.Null(new UiMenu().Selected);
+    }
+
+    [Fact]
+    public void Select_AvailableLeftColumnItem_FiresOnSelect()
+    {
+        var menu = MakeMenu();
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, 5)));   // open
+
+        object? fired = null;
+        menu.OnSelect = p => fired = p;
+
+        // "Chat to All" (Say) is index 2 = left col, row 2: y in [-85,-68). Say is available.
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, -76)));
+        Assert.Equal(ChatChannelKind.Say, fired);
+        Assert.Equal(ChatChannelKind.Say, menu.Selected);
+    }
+
+    [Fact]
+    public void Select_AvailableRightColumnItem_FiresOnSelect()
+    {
+        var menu = MakeMenu();
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, 5)));   // open
+
+        object? fired = null;
+        menu.OnSelect = p => fired = p;
+
+        // "Tell to Trade Chat" (Trade) is index 11 = right col (lx>=191), row 4: y in [-51,-34).
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 200, -42)));
+        Assert.Equal(ChatChannelKind.Trade, fired);
+        Assert.Equal(ChatChannelKind.Trade, menu.Selected);
+    }
+
+    [Fact]
+    public void Select_SpecialItem_DoesNotFire()
+    {
+        var menu = MakeMenu();
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, 5)));   // open
+        int fired = 0;
+        menu.OnSelect = _ => fired++;
+
+        // "Squelch (ignore)" is index 0 = left col, row 0 (null payload): y in [-119,-102).
+        // null payload → ChannelAvailable returns false → inert.
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, -110)));
+        Assert.Equal(0, fired);
+    }
+
+    [Fact]
+    public void Select_UnavailableChannel_DoesNotFire()
+    {
+        var menu = MakeMenu();
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, 5)));   // open
+        int fired = 0;
+        menu.OnSelect = _ => fired++;
+
+        // "Tell to Fellows" (Fellowship) is index 3 = left col, row 3: y in [-68,-51).
+        // Fellowship is unavailable by the default static gate, so the click is inert.
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, -60)));
+        Assert.Equal(0, fired);
+    }
+
+    [Fact]
+    public void EnabledProvider_Overrides_DefaultGate()
+    {
+        // Override: all items enabled (even Fellowship which is normally greyed).
+        var menu = new UiMenu
+        {
+            Width = 80f, Height = 18f,
+            Items = ChannelItems,
+            Selected = (object?)ChatChannelKind.Say,
+            EnabledProvider = _ => true,
+        };
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, 5)));   // open
+
+        object? fired = null;
+        menu.OnSelect = p => fired = p;
+
+        // With every item enabled, "Tell to Fellows" (idx 3, row 3) now fires.
+        Assert.True(menu.OnEvent(new UiEvent(0, menu, UiEventType.MouseDown, 0, 10, -60)));
+        Assert.Equal(ChatChannelKind.Fellowship, fired);
+    }
+}