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>

src/AcDream.Runtime/Gameplay/RuntimeCommunicationState.cs

@@ -66,6 +66,7 @@ public sealed class RuntimeCommunicationState : IDisposable
         TurbineChat = new TurbineChatState();
         Friends = new FriendsState();
         Squelch = new SquelchState();
+        ChatWindows = new ChatWindowState();
         View = new CommunicationView(Chat);
         SocialView = new CommunicationSocialView(
             TurbineChat,
@@ -75,6 +76,15 @@ public sealed class RuntimeCommunicationState : IDisposable
 
     public ChatLog Chat { get; }
 
+    /// <summary>
+    /// Campaign CH slice CH6b: retail's per-window text-type filter and
+    /// open/visible state for the main chat window (id 0) and the four
+    /// floating chat windows (ids 1-4). Graphical, headless, and plugin
+    /// hosts all borrow this exact instance — presentation never owns a
+    /// second copy of filter/open state.
+    /// </summary>
+    public ChatWindowState ChatWindows { get; }
+
     /// <summary>
     /// Campaign CH slice CH2: retail's transient on-screen "interface text"
     /// queue (<c>gmSpewBoxUI</c>) — the SECOND sink <see cref="AddText"/>
@@ -206,6 +216,7 @@ public sealed class RuntimeCommunicationState : IDisposable
         Squelch.Clear();
         Chat.ResetSessionIdentity();
         SpewBox.Reset();
+        ChatWindows.ResetToDefaults();
     }
 
     private sealed class CommunicationView(ChatLog chat) : IRuntimeChatView