feat(ui): Chat tab — channel filters + display prefs + font slider

Phase L.0 (cont.) — fourth tab on the Settings shell. Mixes retail's
CharacterOptions2 chat-channel filter bits (Hear*Chat / TimeStamp /
FilterLanguage / AppearOffline) with a font-size slider that has no
retail bitfield equivalent.

ChatSettings record (9 fields):
 · 5 channel filters: HearGeneralChat, HearTradeChat, HearLFGChat,
   HearRoleplayChat, HearSocietyChat
 · 3 display flags: ShowTimestamps, FilterProfanity, AppearOffline
 · 1 visual: FontSize (10..20 pt)

Local-only this phase per the brainstorm — Hear*Chat flags affect
client-side display filtering only; the server still streams every
channel. Server-sync arrives later when the protocol round-trip is
in place.

SettingsStore grows LoadChat / SaveChat using the existing generic
SaveSection helper. All four non-keybind sections (display, audio,
gameplay, chat) now coexist non-destructively in settings.json.

SettingsVM grows the parallel chat state machine. HasUnsavedChanges,
Save, Cancel, ResetAllToDefaults all cover chat. Constructor signature
adds two more params; existing call sites updated.

SettingsPanel.RenderChatTab replaces the L.0-shell placeholder —
8 Checkbox calls grouped under "Channel filters" + "Display"
headers, plus a font-size SliderFloat. The "Coming soon" placeholder
test was retargeted from "Chat" to "Character" since Chat is no
longer a placeholder.

GameWindow wires SettingsStore.LoadChat / SaveChat + a TODO comment
for the future ChatPanel filter integration (read SettingsVM.ChatDraft
when filtering inbound chat lines).

13 new tests:
 · ChatSettings record (3) — defaults pinned, value equality, with-
   expressions
 · SettingsStore chat (3) — missing-file → defaults, round-trip, all
   four sections coexist
 · SettingsVM chat (5) — initial draft, SetChat marks dirty, Save
   invokes callback, Cancel reverts, ResetAllToDefaults covers
 · SettingsPanel chat tab (2) — checkboxes + slider render only when
   active

dotnet build green (0 warnings); dotnet test 1,289 / 1,289 green
(243 Core.Net + 373 UI.Abstractions + 673 Core).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/GameWindow.cs

@@ -909,6 +909,7 @@ public sealed class GameWindow : IDisposable
                     var persistedDisplay  = settingsStore.LoadDisplay();
                     var persistedAudio    = settingsStore.LoadAudio();
                     var persistedGameplay = settingsStore.LoadGameplay();
+                    var persistedChat     = settingsStore.LoadChat();
 
                     // Apply persisted audio to the engine BEFORE the panel
                     // host starts pushing per-frame so the first frame uses
@@ -987,6 +988,25 @@ public sealed class GameWindow : IDisposable
                             {
                                 Console.WriteLine($"settings: gameplay save failed: {ex.Message}");
                             }
+                        },
+                        persistedChat: persistedChat,
+                        onSaveChat: chat =>
+                        {
+                            try
+                            {
+                                settingsStore.SaveChat(chat);
+                                Console.WriteLine(
+                                    "settings: chat saved to "
+                                    + AcDream.UI.Abstractions.Panels.Settings.SettingsStore.DefaultPath());
+                                // Channel filters affect client-side display
+                                // only this phase. ChatPanel will read them
+                                // off SettingsVM.ChatDraft when filtering is
+                                // wired into the chat-line render path.
+                            }
+                            catch (Exception ex)
+                            {
+                                Console.WriteLine($"settings: chat save failed: {ex.Message}");
+                            }
                         });
                     _settingsPanel = new AcDream.UI.Abstractions.Panels.Settings.SettingsPanel(_settingsVm);
                     _panelHost.Register(_settingsPanel);

src/AcDream.UI.Abstractions/Panels/Settings/ChatSettings.cs

@@ -0,0 +1,44 @@
+namespace AcDream.UI.Abstractions.Panels.Settings;
+
+/// <summary>
+/// Chat-related preferences persisted to <c>settings.json</c>. Mixes
+/// retail's <c>CharacterOptions2</c> chat-channel filter bits (Hear*Chat
+/// + TimeStamp + FilterLanguage + AppearOffline) with a few visual
+/// preferences (font size) that don't have a retail bitfield.
+/// See <c>docs/research/named-retail/acclient.h:3451+</c> for the
+/// retail bit values.
+///
+/// <para>
+/// L.0 scope: <b>local-only</b> like the rest of L.0. The Hear*Chat
+/// flags affect client-side <i>display</i> filtering of the existing
+/// channels — the server still streams every line; the client decides
+/// what to render. Server-sync arrives in a later phase that flips the
+/// retail-faithful "tell server which channels I'm subscribed to"
+/// switch.
+/// </para>
+/// </summary>
+public sealed record ChatSettings(
+    // CharacterOptions2 (32-bit) channel filters.
+    bool HearGeneralChat,                // 0x100   — General channel
+    bool HearTradeChat,                  // 0x200   — Trade channel
+    bool HearLFGChat,                    // 0x400   — LFG channel
+    bool HearRoleplayChat,               // 0x800   — RP channel
+    bool HearSocietyChat,                // 0x80000 — Society chat (CD/EW/RB)
+    bool AppearOffline,                  // 0x1000  — hide /who status
+    bool ShowTimestamps,                 // 0x40    — TimeStamp prefix on chat lines
+    bool FilterProfanity,                // 0x20000 — FilterLanguage (Turbine's profanity filter)
+    // Visual / UX (no retail bitfield).
+    float FontSize)                      // chat panel font, 10..20 pt
+{
+    /// <summary>Sensible starting values matching the retail "all on" stance.</summary>
+    public static ChatSettings Default { get; } = new(
+        HearGeneralChat:    true,
+        HearTradeChat:      true,
+        HearLFGChat:        true,
+        HearRoleplayChat:   true,
+        HearSocietyChat:    true,
+        AppearOffline:      false,
+        ShowTimestamps:     true,
+        FilterProfanity:    true,
+        FontSize:           12f);
+}

src/AcDream.UI.Abstractions/Panels/Settings/SettingsPanel.cs

@@ -98,7 +98,7 @@ public sealed class SettingsPanel : IPanel
             }
             if (renderer.BeginTabItem("Chat"))
             {
-                RenderPlaceholder(renderer, "Chat");
+                RenderChatTab(renderer);
                 renderer.EndTabItem();
             }
             if (renderer.BeginTabItem("Character"))
@@ -356,6 +356,67 @@ public sealed class SettingsPanel : IPanel
             + "follow-up phase.");
     }
 
+    /// <summary>
+    /// Render the Chat tab — channel filters (Hear*Chat), display
+    /// preferences (timestamps / profanity filter / appear offline),
+    /// and a font-size slider. Channel filters affect client-side
+    /// display only this phase — the server still sends every line,
+    /// the client decides what to render.
+    /// </summary>
+    private void RenderChatTab(IPanelRenderer renderer)
+    {
+        var c = _vm.ChatDraft;
+
+        renderer.Text("Channel filters");
+        renderer.Separator();
+
+        bool general = c.HearGeneralChat;
+        if (renderer.Checkbox("General", ref general))
+            _vm.SetChat(c with { HearGeneralChat = general });
+
+        bool trade = c.HearTradeChat;
+        if (renderer.Checkbox("Trade", ref trade))
+            _vm.SetChat(c with { HearTradeChat = trade });
+
+        bool lfg = c.HearLFGChat;
+        if (renderer.Checkbox("LFG (looking for group)", ref lfg))
+            _vm.SetChat(c with { HearLFGChat = lfg });
+
+        bool rp = c.HearRoleplayChat;
+        if (renderer.Checkbox("Roleplay", ref rp))
+            _vm.SetChat(c with { HearRoleplayChat = rp });
+
+        bool society = c.HearSocietyChat;
+        if (renderer.Checkbox("Society (CD / EW / RB)", ref society))
+            _vm.SetChat(c with { HearSocietyChat = society });
+
+        renderer.Spacing();
+        renderer.Text("Display");
+        renderer.Separator();
+
+        bool timestamps = c.ShowTimestamps;
+        if (renderer.Checkbox("Show timestamps", ref timestamps))
+            _vm.SetChat(c with { ShowTimestamps = timestamps });
+
+        bool profanity = c.FilterProfanity;
+        if (renderer.Checkbox("Filter profanity", ref profanity))
+            _vm.SetChat(c with { FilterProfanity = profanity });
+
+        bool offline = c.AppearOffline;
+        if (renderer.Checkbox("Appear offline (hide from /who)", ref offline))
+            _vm.SetChat(c with { AppearOffline = offline });
+
+        float fontSize = c.FontSize;
+        if (renderer.SliderFloat("Font size (pt)", ref fontSize, 10f, 20f))
+            _vm.SetChat(c with { FontSize = fontSize });
+
+        renderer.Spacing();
+        renderer.TextWrapped(
+            "Channel filters hide messages from the chat window without "
+            + "changing your server-side subscriptions. Save persists; "
+            + "Cancel reverts.");
+    }
+
     private void RenderSection(IPanelRenderer renderer, string label, InputAction[] actions)
     {
         // Movement defaults open; other sections collapsed for first-run UX.

src/AcDream.UI.Abstractions/Panels/Settings/SettingsStore.cs

@@ -167,6 +167,56 @@ public sealed class SettingsStore
     public void SaveGameplay(GameplaySettings gameplay)
         => SaveSection("gameplay", BuildGameplayObject(gameplay));
 
+    /// <summary>Load Chat settings. Same fall-back behaviour as <see cref="LoadDisplay"/>.</summary>
+    public ChatSettings LoadChat()
+    {
+        if (!File.Exists(_path)) return ChatSettings.Default;
+        try
+        {
+            using var stream = File.OpenRead(_path);
+            var doc  = JsonDocument.Parse(stream);
+            var root = doc.RootElement;
+            if (!root.TryGetProperty("chat", out var chat)
+                || chat.ValueKind != JsonValueKind.Object)
+                return ChatSettings.Default;
+
+            var d = ChatSettings.Default;
+            return new ChatSettings(
+                HearGeneralChat:  ReadBool (chat, "hearGeneralChat",  d.HearGeneralChat),
+                HearTradeChat:    ReadBool (chat, "hearTradeChat",    d.HearTradeChat),
+                HearLFGChat:      ReadBool (chat, "hearLFGChat",      d.HearLFGChat),
+                HearRoleplayChat: ReadBool (chat, "hearRoleplayChat", d.HearRoleplayChat),
+                HearSocietyChat:  ReadBool (chat, "hearSocietyChat",  d.HearSocietyChat),
+                AppearOffline:    ReadBool (chat, "appearOffline",    d.AppearOffline),
+                ShowTimestamps:   ReadBool (chat, "showTimestamps",   d.ShowTimestamps),
+                FilterProfanity:  ReadBool (chat, "filterProfanity",  d.FilterProfanity),
+                FontSize:         ReadFloat(chat, "fontSize",         d.FontSize));
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"settings: failed to load {_path}: {ex.Message} — using defaults");
+            return ChatSettings.Default;
+        }
+    }
+
+    /// <summary>Save Chat settings, preserving all other top-level keys.</summary>
+    public void SaveChat(ChatSettings chat)
+        => SaveSection("chat", BuildChatObject(chat));
+
+    private static SortedDictionary<string, object> BuildChatObject(ChatSettings c)
+        => new(StringComparer.Ordinal)
+        {
+            ["appearOffline"]    = c.AppearOffline,
+            ["filterProfanity"]  = c.FilterProfanity,
+            ["fontSize"]         = c.FontSize,
+            ["hearGeneralChat"]  = c.HearGeneralChat,
+            ["hearLFGChat"]      = c.HearLFGChat,
+            ["hearRoleplayChat"] = c.HearRoleplayChat,
+            ["hearSocietyChat"]  = c.HearSocietyChat,
+            ["hearTradeChat"]    = c.HearTradeChat,
+            ["showTimestamps"]   = c.ShowTimestamps,
+        };
+
     private static SortedDictionary<string, object> BuildGameplayObject(GameplaySettings g)
         => new(StringComparer.Ordinal)
         {

src/AcDream.UI.Abstractions/Panels/Settings/SettingsVM.cs

@@ -46,6 +46,11 @@ public sealed class SettingsVM
     private GameplaySettings _gameplayDraft;
     private readonly Action<GameplaySettings> _onSaveGameplay;
 
+    // L.0 — Chat tab (CharacterOptions2 channel filters + visual prefs).
+    private ChatSettings _chatPersisted;
+    private ChatSettings _chatDraft;
+    private readonly Action<ChatSettings> _onSaveChat;
+
     /// <summary>The action currently being rebound, or null when idle.</summary>
     public InputAction? RebindInProgress { get; private set; }
 
@@ -70,7 +75,8 @@ public sealed class SettingsVM
         => !KeyBindingsEqual(_persisted, _draft)
            || _displayPersisted  != _displayDraft
            || _audioPersisted    != _audioDraft
-           || _gameplayPersisted != _gameplayDraft;
+           || _gameplayPersisted != _gameplayDraft
+           || _chatPersisted     != _chatDraft;
 
     /// <summary>The current Display draft. Panel reads from here;
     /// mutation goes through <see cref="SetDisplay"/>.</summary>
@@ -84,6 +90,10 @@ public sealed class SettingsVM
     /// mutation goes through <see cref="SetGameplay"/>.</summary>
     public GameplaySettings GameplayDraft => _gameplayDraft;
 
+    /// <summary>The current Chat draft. Panel reads from here;
+    /// mutation goes through <see cref="SetChat"/>.</summary>
+    public ChatSettings ChatDraft => _chatDraft;
+
     public SettingsVM(
         KeyBindings persisted,
         InputDispatcher dispatcher,
@@ -93,7 +103,9 @@ public sealed class SettingsVM
         AudioSettings persistedAudio,
         Action<AudioSettings> onSaveAudio,
         GameplaySettings persistedGameplay,
-        Action<GameplaySettings> onSaveGameplay)
+        Action<GameplaySettings> onSaveGameplay,
+        ChatSettings persistedChat,
+        Action<ChatSettings> onSaveChat)
     {
         _persisted         = persisted         ?? throw new ArgumentNullException(nameof(persisted));
         _dispatcher        = dispatcher        ?? throw new ArgumentNullException(nameof(dispatcher));
@@ -104,10 +116,13 @@ public sealed class SettingsVM
         _onSaveAudio       = onSaveAudio       ?? throw new ArgumentNullException(nameof(onSaveAudio));
         _gameplayPersisted = persistedGameplay ?? throw new ArgumentNullException(nameof(persistedGameplay));
         _onSaveGameplay    = onSaveGameplay    ?? throw new ArgumentNullException(nameof(onSaveGameplay));
+        _chatPersisted     = persistedChat     ?? throw new ArgumentNullException(nameof(persistedChat));
+        _onSaveChat        = onSaveChat        ?? throw new ArgumentNullException(nameof(onSaveChat));
         _draft             = CloneBindings(persisted);
         _displayDraft      = persistedDisplay;
         _audioDraft        = persistedAudio;
         _gameplayDraft     = persistedGameplay;
+        _chatDraft         = persistedChat;
     }
 
     /// <summary>
@@ -144,6 +159,17 @@ public sealed class SettingsVM
         _gameplayDraft = value ?? throw new ArgumentNullException(nameof(value));
     }
 
+    /// <summary>
+    /// Replace the entire Chat draft with <paramref name="value"/>.
+    /// Local-only this phase — values persist on Save but the Hear*Chat
+    /// flags affect client-side display filtering, not server-side
+    /// channel subscriptions.
+    /// </summary>
+    public void SetChat(ChatSettings value)
+    {
+        _chatDraft = value ?? throw new ArgumentNullException(nameof(value));
+    }
+
     /// <summary>
     /// Begin rebinding <paramref name="action"/>. The supplied
     /// <paramref name="original"/> binding will be removed when the new
@@ -255,6 +281,7 @@ public sealed class SettingsVM
         _displayDraft  = DisplaySettings.Default;
         _audioDraft    = AudioSettings.Default;
         _gameplayDraft = GameplaySettings.Default;
+        _chatDraft     = ChatSettings.Default;
     }
 
     /// <summary>
@@ -271,10 +298,12 @@ public sealed class SettingsVM
         _onSaveDisplay(_displayDraft);
         _onSaveAudio(_audioDraft);
         _onSaveGameplay(_gameplayDraft);
+        _onSaveChat(_chatDraft);
         _persisted         = CloneBindings(_draft);
         _displayPersisted  = _displayDraft;
         _audioPersisted    = _audioDraft;
         _gameplayPersisted = _gameplayDraft;
+        _chatPersisted     = _chatDraft;
     }
 
     /// <summary>
@@ -288,6 +317,7 @@ public sealed class SettingsVM
         _displayDraft  = _displayPersisted;
         _audioDraft    = _audioPersisted;
         _gameplayDraft = _gameplayPersisted;
+        _chatDraft     = _chatPersisted;
         CancelRebind();
     }
 

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

@@ -0,0 +1,43 @@
+using AcDream.UI.Abstractions.Panels.Settings;
+
+namespace AcDream.UI.Abstractions.Tests.Panels.Settings;
+
+/// <summary>
+/// L.0: <see cref="ChatSettings"/> default-pin tests.
+/// </summary>
+public sealed class ChatSettingsTests
+{
+    [Fact]
+    public void Default_values_are_all_channels_on_with_timestamps_and_filter()
+    {
+        var d = ChatSettings.Default;
+        Assert.True(d.HearGeneralChat);
+        Assert.True(d.HearTradeChat);
+        Assert.True(d.HearLFGChat);
+        Assert.True(d.HearRoleplayChat);
+        Assert.True(d.HearSocietyChat);
+        Assert.False(d.AppearOffline);
+        Assert.True(d.ShowTimestamps);
+        Assert.True(d.FilterProfanity);
+        Assert.Equal(12f, d.FontSize);
+    }
+
+    [Fact]
+    public void Equality_is_value_based()
+    {
+        var a = ChatSettings.Default;
+        var b = ChatSettings.Default with { HearTradeChat = false };
+        var c = ChatSettings.Default with { HearTradeChat = false };
+        Assert.NotEqual(a, b);
+        Assert.Equal(b, c);
+    }
+
+    [Fact]
+    public void With_expression_clones_one_field()
+    {
+        var d = ChatSettings.Default with { FontSize = 16f };
+        Assert.Equal(16f, d.FontSize);
+        Assert.True(d.HearGeneralChat);
+        Assert.True(d.ShowTimestamps);
+    }
+}

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

@@ -33,7 +33,8 @@ public sealed class SettingsPanelTests
             persisted, dispatcher, _ => { },
             DisplaySettings.Default, _ => { },
             AudioSettings.Default, _ => { },
-            GameplaySettings.Default, _ => { });
+            GameplaySettings.Default, _ => { },
+            ChatSettings.Default, _ => { });
         var panel = new SettingsPanel(vm);
         return (panel, vm, kb, dispatcher);
     }
@@ -228,17 +229,17 @@ public sealed class SettingsPanelTests
     [Fact]
     public void Placeholder_tabs_render_coming_soon_text_when_active()
     {
-        // Chat is still a placeholder (next in build order). Display,
+        // Character is still a placeholder (last on the build order).
-        // Audio, and Gameplay have shipped — they have real widgets,
+        // Display / Audio / Gameplay / Chat have shipped — they have
-        // not "coming soon" text.
+        // real widgets, not "coming soon" text.
         var (panel, _, _, _) = Build();
-        var r = new FakePanelRenderer { ActiveTabLabel = "Chat" };
+        var r = new FakePanelRenderer { ActiveTabLabel = "Character" };
 
         panel.Render(new PanelContext(0.016f, new NullBus()), r);
 
         var wrapped = r.Calls.Where(c => c.Method == "TextWrapped")
             .Select(c => (string)c.Args[0]!).ToList();
-        Assert.Contains(wrapped, t => t.Contains("Chat settings coming soon"));
+        Assert.Contains(wrapped, t => t.Contains("Character settings coming soon"));
     }
 
     // -- Display tab content ---------------------------------------------
@@ -359,6 +360,48 @@ public sealed class SettingsPanelTests
         Assert.DoesNotContain("Lock UI (disable panel drag/resize)", checks);
     }
 
+    // -- Chat tab content ------------------------------------------------
+
+    [Fact]
+    public void Chat_tab_when_active_renders_channel_filter_checkboxes_and_font_slider()
+    {
+        var (panel, _, _, _) = Build();
+        var r = new FakePanelRenderer { ActiveTabLabel = "Chat" };
+
+        panel.Render(new PanelContext(0.016f, new NullBus()), r);
+
+        var checks = r.Calls.Where(c => c.Method == "Checkbox")
+            .Select(c => (string)c.Args[0]!).ToList();
+        Assert.Contains("General", checks);
+        Assert.Contains("Trade", checks);
+        Assert.Contains("LFG (looking for group)", checks);
+        Assert.Contains("Roleplay", checks);
+        Assert.Contains("Society (CD / EW / RB)", checks);
+        Assert.Contains("Show timestamps", checks);
+        Assert.Contains("Filter profanity", checks);
+        Assert.Contains("Appear offline (hide from /who)", checks);
+
+        var sliders = r.Calls.Where(c => c.Method == "SliderFloat")
+            .Select(c => (string)c.Args[0]!).ToList();
+        Assert.Contains("Font size (pt)", sliders);
+    }
+
+    [Fact]
+    public void Chat_tab_does_not_render_when_a_different_tab_is_active()
+    {
+        var (panel, _, _, _) = Build();
+        var r = new FakePanelRenderer { ActiveTabLabel = "Display" };
+
+        panel.Render(new PanelContext(0.016f, new NullBus()), r);
+
+        var checks = r.Calls.Where(c => c.Method == "Checkbox")
+            .Select(c => (string)c.Args[0]!).ToList();
+        // The tab labels "General", "Trade" etc only appear inside the
+        // Chat tab. Confirm none of them rendered.
+        Assert.DoesNotContain("General", checks);
+        Assert.DoesNotContain("Trade", checks);
+    }
+
     [Fact]
     public void Audio_sliders_are_clamped_to_zero_one_range()
     {

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

@@ -240,4 +240,48 @@ public sealed class SettingsStoreTests : System.IDisposable
         Assert.Equal(0.5f, store.LoadAudio().Master);
         Assert.True(store.LoadGameplay().LockUI);
     }
+
+    // -- Chat section round-trip ------------------------------------------
+
+    [Fact]
+    public void LoadChat_returns_defaults_when_file_is_missing()
+    {
+        var store = new SettingsStore(_tempPath);
+        Assert.Equal(ChatSettings.Default, store.LoadChat());
+    }
+
+    [Fact]
+    public void SaveChat_then_LoadChat_round_trips_all_fields()
+    {
+        var store = new SettingsStore(_tempPath);
+        var original = new ChatSettings(
+            HearGeneralChat:  false,
+            HearTradeChat:    false,
+            HearLFGChat:      false,
+            HearRoleplayChat: true,
+            HearSocietyChat:  true,
+            AppearOffline:    true,
+            ShowTimestamps:   false,
+            FilterProfanity:  false,
+            FontSize:         16f);
+
+        store.SaveChat(original);
+        Assert.Equal(original, store.LoadChat());
+    }
+
+    [Fact]
+    public void All_four_sections_coexist_in_one_settings_json()
+    {
+        var store = new SettingsStore(_tempPath);
+        store.SaveDisplay(DisplaySettings.Default with { Resolution = "2560x1440" });
+        store.SaveAudio(AudioSettings.Default with { Master = 0.5f });
+        store.SaveGameplay(GameplaySettings.Default with { LockUI = true });
+        store.SaveChat(ChatSettings.Default with { HearTradeChat = false, FontSize = 14f });
+
+        Assert.Equal("2560x1440", store.LoadDisplay().Resolution);
+        Assert.Equal(0.5f, store.LoadAudio().Master);
+        Assert.True(store.LoadGameplay().LockUI);
+        Assert.False(store.LoadChat().HearTradeChat);
+        Assert.Equal(14f, store.LoadChat().FontSize);
+    }
 }

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

@@ -16,8 +16,8 @@ namespace AcDream.UI.Abstractions.Tests.Panels.Settings;
 /// </summary>
 public sealed class SettingsVMTests
 {
-    private static (SettingsVM vm, FakeKeyboardSource kb, InputDispatcher dispatcher, KeyBindings persisted, System.Collections.Generic.List<KeyBindings> savedHistory, System.Collections.Generic.List<DisplaySettings> savedDisplayHistory, System.Collections.Generic.List<AudioSettings> savedAudioHistory, System.Collections.Generic.List<GameplaySettings> savedGameplayHistory)
+    private static (SettingsVM vm, FakeKeyboardSource kb, InputDispatcher dispatcher, KeyBindings persisted, System.Collections.Generic.List<KeyBindings> savedHistory, System.Collections.Generic.List<DisplaySettings> savedDisplayHistory, System.Collections.Generic.List<AudioSettings> savedAudioHistory, System.Collections.Generic.List<GameplaySettings> savedGameplayHistory, System.Collections.Generic.List<ChatSettings> savedChatHistory)
-        Build(KeyBindings? persisted = null, DisplaySettings? persistedDisplay = null, AudioSettings? persistedAudio = null, GameplaySettings? persistedGameplay = null)
+        Build(KeyBindings? persisted = null, DisplaySettings? persistedDisplay = null, AudioSettings? persistedAudio = null, GameplaySettings? persistedGameplay = null, ChatSettings? persistedChat = null)
     {
         persisted ??= MakeMinimalBindings();
         var kb = new FakeKeyboardSource();
@@ -27,6 +27,7 @@ public sealed class SettingsVMTests
         var savedDisplayHistory = new System.Collections.Generic.List<DisplaySettings>();
         var savedAudioHistory = new System.Collections.Generic.List<AudioSettings>();
         var savedGameplayHistory = new System.Collections.Generic.List<GameplaySettings>();
+        var savedChatHistory = new System.Collections.Generic.List<ChatSettings>();
         var vm = new SettingsVM(
             persisted, dispatcher,
             b => savedHistory.Add(b),
@@ -35,8 +36,10 @@ public sealed class SettingsVMTests
             persistedAudio ?? AudioSettings.Default,
             a => savedAudioHistory.Add(a),
             persistedGameplay ?? GameplaySettings.Default,
-            g => savedGameplayHistory.Add(g));
+            g => savedGameplayHistory.Add(g),
-        return (vm, kb, dispatcher, persisted, savedHistory, savedDisplayHistory, savedAudioHistory, savedGameplayHistory);
+            persistedChat ?? ChatSettings.Default,
+            c => savedChatHistory.Add(c));
+        return (vm, kb, dispatcher, persisted, savedHistory, savedDisplayHistory, savedAudioHistory, savedGameplayHistory, savedChatHistory);
     }
 
     private static KeyBindings MakeMinimalBindings()
@@ -51,7 +54,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Constructor_clones_persisted_into_draft()
     {
-        var (vm, _, _, persisted, _, _, _, _) = Build();
+        var (vm, _, _, persisted, _, _, _, _, _) = Build();
         Assert.Equal(persisted.All.Count, vm.Draft.All.Count);
         Assert.False(vm.HasUnsavedChanges);
     }
@@ -59,7 +62,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void BeginRebind_enters_capture_mode()
     {
-        var (vm, _, dispatcher, _, _, _, _, _) = Build();
+        var (vm, _, dispatcher, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         vm.BeginRebind(InputAction.MovementForward, original);
@@ -72,7 +75,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void BeginRebind_then_chord_with_no_conflict_applies_rebind()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         vm.BeginRebind(InputAction.MovementForward, original);
@@ -90,7 +93,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void BeginRebind_then_Escape_cancels_with_no_change()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         vm.BeginRebind(InputAction.MovementForward, original);
@@ -107,7 +110,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void BeginRebind_with_conflict_surfaces_PendingConflict()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         // Bind chord that conflicts with MovementTurnLeft (which has Key.A).
@@ -127,7 +130,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void ResolveConflict_replace_true_removes_conflict_and_applies_rebind()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         vm.BeginRebind(InputAction.MovementForward, original);
@@ -148,7 +151,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void ResolveConflict_replace_false_cancels_rebind()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
 
         vm.BeginRebind(InputAction.MovementForward, original);
@@ -170,7 +173,7 @@ public sealed class SettingsVMTests
     {
         // Build a draft that's been mutated for MovementForward; ensure
         // ResetActionToDefault restores W (and Up-arrow per retail).
-        var (vm, kb, _, _, _, _, _, _) = Build(KeyBindings.RetailDefaults());
+        var (vm, kb, _, _, _, _, _, _, _) = Build(KeyBindings.RetailDefaults());
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
         vm.BeginRebind(InputAction.MovementForward, original);
         // F7 is unbound in retail-default (only Ctrl+F7 is acdream debug);
@@ -190,7 +193,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void ResetAllToDefaults_replaces_entire_draft()
     {
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         vm.ResetAllToDefaults();
 
         // Should now include retail-default size set (~149 bindings).
@@ -201,7 +204,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Save_invokes_callback_with_draft()
     {
-        var (vm, kb, _, _, savedHistory, _, _, _) = Build();
+        var (vm, kb, _, _, savedHistory, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
         vm.BeginRebind(InputAction.MovementForward, original);
         kb.EmitKeyDown(Key.Q, ModifierMask.None);
@@ -217,7 +220,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Cancel_reverts_draft_to_persisted()
     {
-        var (vm, kb, _, _, _, _, _, _) = Build();
+        var (vm, kb, _, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
         vm.BeginRebind(InputAction.MovementForward, original);
         kb.EmitKeyDown(Key.Q, ModifierMask.None);
@@ -233,7 +236,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Cancel_during_active_capture_clears_dispatcher_capture_state()
     {
-        var (vm, _, dispatcher, _, _, _, _, _) = Build();
+        var (vm, _, dispatcher, _, _, _, _, _, _) = Build();
         var original = vm.Draft.ForAction(InputAction.MovementForward).First();
         vm.BeginRebind(InputAction.MovementForward, original);
 
@@ -246,7 +249,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void HasUnsavedChanges_false_initially_and_after_save_sync()
     {
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         Assert.False(vm.HasUnsavedChanges);
     }
 
@@ -256,7 +259,7 @@ public sealed class SettingsVMTests
     public void DisplayDraft_initial_value_matches_persisted()
     {
         var custom = DisplaySettings.Default with { FieldOfView = 90f, ShowFps = true };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
         Assert.Equal(custom, vm.DisplayDraft);
         Assert.False(vm.HasUnsavedChanges);
     }
@@ -264,7 +267,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void SetDisplay_marks_unsaved_changes()
     {
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         vm.SetDisplay(vm.DisplayDraft with { ShowFps = true });
         Assert.True(vm.HasUnsavedChanges);
     }
@@ -272,7 +275,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Save_invokes_display_callback_with_draft()
     {
-        var (vm, _, _, _, _, savedDisplayHistory, _, _) = Build();
+        var (vm, _, _, _, _, savedDisplayHistory, _, _, _) = Build();
         vm.SetDisplay(vm.DisplayDraft with { Resolution = "2560x1440", FieldOfView = 100f });
 
         vm.Save();
@@ -287,7 +290,7 @@ public sealed class SettingsVMTests
     public void Cancel_reverts_display_draft_to_persisted()
     {
         var custom = DisplaySettings.Default with { FieldOfView = 90f };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
         vm.SetDisplay(vm.DisplayDraft with { FieldOfView = 30f, ShowFps = true });
         Assert.True(vm.HasUnsavedChanges);
 
@@ -301,7 +304,7 @@ public sealed class SettingsVMTests
     public void ResetAllToDefaults_resets_display_to_default()
     {
         var custom = DisplaySettings.Default with { FieldOfView = 30f, ShowFps = true };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedDisplay: custom);
         Assert.NotEqual(DisplaySettings.Default, vm.DisplayDraft);
 
         vm.ResetAllToDefaults();
@@ -316,7 +319,7 @@ public sealed class SettingsVMTests
         // After Save the persisted snapshot equals the draft, so Cancel
         // is a no-op. This guards the Save/Cancel ordering — a regression
         // would surface as Cancel reverting to pre-Save values.
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         vm.SetDisplay(vm.DisplayDraft with { ShowFps = true });
         vm.Save();
         Assert.False(vm.HasUnsavedChanges);
@@ -333,7 +336,7 @@ public sealed class SettingsVMTests
     public void AudioDraft_initial_value_matches_persisted()
     {
         var custom = AudioSettings.Default with { Master = 0.3f, Music = 0.1f };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
         Assert.Equal(custom, vm.AudioDraft);
         Assert.False(vm.HasUnsavedChanges);
     }
@@ -341,7 +344,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void SetAudio_marks_unsaved_changes()
     {
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         vm.SetAudio(vm.AudioDraft with { Master = 0.5f });
         Assert.True(vm.HasUnsavedChanges);
     }
@@ -349,7 +352,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Save_invokes_audio_callback_with_draft()
     {
-        var (vm, _, _, _, _, _, savedAudioHistory, _) = Build();
+        var (vm, _, _, _, _, _, savedAudioHistory, _, _) = Build();
         vm.SetAudio(vm.AudioDraft with { Master = 0.4f, Sfx = 0.6f });
 
         vm.Save();
@@ -364,7 +367,7 @@ public sealed class SettingsVMTests
     public void Cancel_reverts_audio_draft_to_persisted()
     {
         var custom = AudioSettings.Default with { Music = 0.2f };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
         vm.SetAudio(vm.AudioDraft with { Music = 0.9f, Master = 0.3f });
         Assert.True(vm.HasUnsavedChanges);
 
@@ -378,7 +381,7 @@ public sealed class SettingsVMTests
     public void ResetAllToDefaults_resets_audio_to_default()
     {
         var custom = AudioSettings.Default with { Master = 0.1f };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedAudio: custom);
         Assert.NotEqual(AudioSettings.Default, vm.AudioDraft);
 
         vm.ResetAllToDefaults();
@@ -393,7 +396,7 @@ public sealed class SettingsVMTests
     public void GameplayDraft_initial_value_matches_persisted()
     {
         var custom = GameplaySettings.Default with { AutoTarget = false, LockUI = true };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
         Assert.Equal(custom, vm.GameplayDraft);
         Assert.False(vm.HasUnsavedChanges);
     }
@@ -401,7 +404,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void SetGameplay_marks_unsaved_changes()
     {
-        var (vm, _, _, _, _, _, _, _) = Build();
+        var (vm, _, _, _, _, _, _, _, _) = Build();
         vm.SetGameplay(vm.GameplayDraft with { LockUI = true });
         Assert.True(vm.HasUnsavedChanges);
     }
@@ -409,7 +412,7 @@ public sealed class SettingsVMTests
     [Fact]
     public void Save_invokes_gameplay_callback_with_draft()
     {
-        var (vm, _, _, _, _, _, _, savedGameplayHistory) = Build();
+        var (vm, _, _, _, _, _, _, savedGameplayHistory, _) = Build();
         vm.SetGameplay(vm.GameplayDraft with
         {
             AutoTarget = false,
@@ -430,7 +433,7 @@ public sealed class SettingsVMTests
     public void Cancel_reverts_gameplay_draft_to_persisted()
     {
         var custom = GameplaySettings.Default with { LockUI = true };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
         vm.SetGameplay(vm.GameplayDraft with { LockUI = false, ShowHelm = false });
         Assert.True(vm.HasUnsavedChanges);
 
@@ -444,7 +447,7 @@ public sealed class SettingsVMTests
     public void ResetAllToDefaults_resets_gameplay_to_default()
     {
         var custom = GameplaySettings.Default with { AutoTarget = false, LockUI = true };
-        var (vm, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedGameplay: custom);
         Assert.NotEqual(GameplaySettings.Default, vm.GameplayDraft);
 
         vm.ResetAllToDefaults();
@@ -452,4 +455,64 @@ public sealed class SettingsVMTests
         Assert.Equal(GameplaySettings.Default, vm.GameplayDraft);
         Assert.True(vm.HasUnsavedChanges);
     }
+
+    // -- Chat tab state ---------------------------------------------------
+
+    [Fact]
+    public void ChatDraft_initial_value_matches_persisted()
+    {
+        var custom = ChatSettings.Default with { HearTradeChat = false, FontSize = 14f };
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedChat: custom);
+        Assert.Equal(custom, vm.ChatDraft);
+        Assert.False(vm.HasUnsavedChanges);
+    }
+
+    [Fact]
+    public void SetChat_marks_unsaved_changes()
+    {
+        var (vm, _, _, _, _, _, _, _, _) = Build();
+        vm.SetChat(vm.ChatDraft with { FontSize = 16f });
+        Assert.True(vm.HasUnsavedChanges);
+    }
+
+    [Fact]
+    public void Save_invokes_chat_callback_with_draft()
+    {
+        var (vm, _, _, _, _, _, _, _, savedChatHistory) = Build();
+        vm.SetChat(vm.ChatDraft with { HearTradeChat = false, ShowTimestamps = false });
+
+        vm.Save();
+
+        Assert.Single(savedChatHistory);
+        Assert.False(savedChatHistory[0].HearTradeChat);
+        Assert.False(savedChatHistory[0].ShowTimestamps);
+        Assert.False(vm.HasUnsavedChanges);
+    }
+
+    [Fact]
+    public void Cancel_reverts_chat_draft_to_persisted()
+    {
+        var custom = ChatSettings.Default with { HearLFGChat = false };
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedChat: custom);
+        vm.SetChat(vm.ChatDraft with { HearLFGChat = true, AppearOffline = true });
+        Assert.True(vm.HasUnsavedChanges);
+
+        vm.Cancel();
+
+        Assert.Equal(custom, vm.ChatDraft);
+        Assert.False(vm.HasUnsavedChanges);
+    }
+
+    [Fact]
+    public void ResetAllToDefaults_resets_chat_to_default()
+    {
+        var custom = ChatSettings.Default with { HearGeneralChat = false, FontSize = 18f };
+        var (vm, _, _, _, _, _, _, _, _) = Build(persistedChat: custom);
+        Assert.NotEqual(ChatSettings.Default, vm.ChatDraft);
+
+        vm.ResetAllToDefaults();
+
+        Assert.Equal(ChatSettings.Default, vm.ChatDraft);
+        Assert.True(vm.HasUnsavedChanges);
+    }
 }