feat(chat): Campaign CH slice CH6b — floating chat windows 1-4

Mounts retail's four floating chat windows as always-resident, born-hidden
children per gmGamePlayUI::SetupChildren @0x004E9EC0, all sharing LayoutDesc
0x2100005B (window ids 0x10000505/0x1000050E/0x1000050F/0x10000510). New
FloatingChatWindowController (AcDream.App/UI/Layout) binds each window's own
widget tree — built fresh per instance from one shared imported ElementInfo
— reusing ChatWindowController's word-wrap + retail color-carry algorithm via
the extracted ChatTranscriptRenderer instead of duplicating it. A floaty
window has no talk-focus menu (research doc §2.2), so its entry field always
sends on Say; the mismatch against retail's possible shared-channel behavior
is UNVERIFIED and filed as #369/AP-188.

Runtime owns the per-window filter/open state: ChatWindowState (new,
AcDream.Core.Chat) seeds retail's exact PostInit defaults per window
(window 1 0x0000101C Speech/Tell/DirectSend/Emote, window 2 0x00040C00
Social/SocialSend/Allegiance, window 3 0x00080000 Fellowship, window 4
0x78000000 Turbine General/Trade/LFG/Roleplay) and implements the full
ShouldDisplay(windowId, targetWindowId, logTextType) display predicate from
ChatInterface::RecvNotice_DisplayFinalStringInfo @0x004F4640. It lives on
RuntimeCommunicationState.ChatWindows so every host borrows the same
instance. The main window's filter (0xFBFFFFFF, "no user filter") never
actually gates anything because its own explicit-address branch already
covers every broadcast line — that's why UpdateFromPlayerModule early-returns
for window 0 in retail, ported here by construction rather than a special
case.

Keybind wiring: InputAction.ToggleFloatingChatWindow1..4 and their
KeyBindings.RetailDefaults() chords already existed since Phase K.1c
(unwired until now). The MetaKeys table confirms retail's default is Alt+1
through Alt+4 (index 3 = bit 0x00000004, cross-checked against the same
file's Alt+A/D strafe and Alt+Enter/Tab/F4 rows). Routes through
GameplayInputCommandController -> RetainedGameplayWindowCommands ->
RetailUiRuntime.ToggleFloatingChatWindow -> the generic UiHost.ToggleWindow,
whose visibility-change event is the single chokepoint that syncs
ChatWindowState.SetOpen and mirrors the main window's 1-4 indicator button
regardless of what changed a window's visibility (keybind, close button, or
a restored layout).

A direct decomp read of gmMainChatUI::ListenToElementMessage @0x004CDA80 —
the only function in the whole binary that branches on a click message —
settles what the research doc had left as a hedge: it handles exactly
0x1000046f (max/min) and the talk-focus menu's selection message, with NO
case for 0x10000522-0x10000525. The four indicator buttons are PURE
one-directional mirrors in retail; clicking them does nothing.
ChatWindowController.SetIndicatorOpen ports this with no OnClick at all.
Corrected research doc §1.4 accordingly.

Persistence is local-only (register row AP-187; the retail 0x1000008C
GameplayOptions wire remains deferred to CH6f): window geometry and
open/visible state ride the existing generic RetailWindowLayoutPersistence
path for free once each window registers under its own WindowNames entry;
the four filter masks get a dedicated ChatSettings round-trip
(ChatWindow1Filter..ChatWindow4Filter, defaulting to the retail PostInit
constants) loaded at mount and saved alongside SaveLayout().

Tests: ChatWindowStateTests (defaults, TypeIsActive, the full display-rule
matrix, toggle/reset, revision counter), FloatingChatWindowControllerTests
(bind smoke tests against a synthetic 0x2100005B tree, per-window filter
routing, filter-change cache invalidation, fixed-Say submit), new
ChatWindowController.SetIndicatorOpen tests (Highlight/Normal state,
cross-window isolation, range validation), GameplayInputCommandController
routing for the four toggle actions, and a SettingsStore filter round-trip.
Full Release suite: 12,392 passed / 4 skipped / 0 failed.

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

tests/AcDream.UI.Abstractions.Tests/Panels/Settings/SettingsStoreTests.cs

@@ -295,6 +295,41 @@ public sealed class SettingsStoreTests : System.IDisposable
         Assert.Equal(original, store.LoadChat());
     }
 
+    // -- Campaign CH slice CH6b: floating chat window filter round-trip ---
+
+    [Fact]
+    public void LoadChat_returns_retail_PostInit_filter_defaults_when_file_is_missing()
+    {
+        var store = new SettingsStore(_tempPath);
+        ChatSettings loaded = store.LoadChat();
+
+        Assert.Equal(0x0000101Cu, loaded.ChatWindow1Filter);
+        Assert.Equal(0x00040C00u, loaded.ChatWindow2Filter);
+        Assert.Equal(0x00080000u, loaded.ChatWindow3Filter);
+        Assert.Equal(0x78000000u, loaded.ChatWindow4Filter);
+    }
+
+    [Fact]
+    public void SaveChat_then_LoadChat_round_trips_floating_window_filters()
+    {
+        var store = new SettingsStore(_tempPath);
+        var original = ChatSettings.Default with
+        {
+            ChatWindow1Filter = 0x1u,
+            ChatWindow2Filter = 0xFFFFFFFFu,
+            ChatWindow3Filter = 0x8000000000000000u, // exercises the high dword (Society/reserved bits)
+            ChatWindow4Filter = 0ul,
+        };
+
+        store.SaveChat(original);
+        ChatSettings loaded = store.LoadChat();
+
+        Assert.Equal(original.ChatWindow1Filter, loaded.ChatWindow1Filter);
+        Assert.Equal(original.ChatWindow2Filter, loaded.ChatWindow2Filter);
+        Assert.Equal(original.ChatWindow3Filter, loaded.ChatWindow3Filter);
+        Assert.Equal(original.ChatWindow4Filter, loaded.ChatWindow4Filter);
+    }
+
     [Fact]
     public void All_four_sections_coexist_in_one_settings_json()
     {