feat: add autohide after inactivity

After not receiving a message for X seconds (configurable) in the
current tab or any tab with unread mode enabled, the chat will be
hidden. Focus can be returned with return or slash as usual.

Having input focus or hovering the mouse over the chat window "bumps"
it every frame.

Also fixes a bug that prevented focus from being restored to tabs with
input disabled. The chat window will be brought back but the activated
event won't be fully processed.

Co-authored-by: Auri <me@aurieh.me>

ChatTwo/Ui/SettingsTabs/Display.cs

@@ -1,7 +1,5 @@
 using ChatTwo.Resources;
 using ChatTwo.Util;
-using Dalamud.Interface.Style;
-using Dalamud.Interface.Utility.Raii;
 using ImGuiNET;
 
 namespace ChatTwo.Ui.SettingsTabs;
@@ -39,6 +37,19 @@ internal sealed class Display : ISettingsTab
         ImGuiUtil.OptionCheckbox(ref Mutable.HideInBattle, Language.Options_HideInBattle_Name, Language.Options_HideInBattle_Description);
         ImGui.Spacing();
 
+        ImGuiUtil.OptionCheckbox(ref Mutable.HideWhenInactive, Language.Options_HideWhenInactive_Name, Language.Options_HideWhenInactive_Description);
+        ImGui.Spacing();
+
+        if (Mutable.HideWhenInactive)
+        {
+            ImGuiUtil.InputIntVertical(Language.Options_InactivityHideTimeout_Name,
+                Language.Options_InactivityHideTimeout_Description, ref Mutable.InactivityHideTimeout, 1, 10);
+            // Enforce a minimum of 2 seconds to avoid people soft locking
+            // themselves.
+            Mutable.InactivityHideTimeout = Math.Max(2, Mutable.InactivityHideTimeout);
+            ImGui.Spacing();
+        }
+
         ImGuiUtil.OptionCheckbox(ref Mutable.PrettierTimestamps, Language.Options_PrettierTimestamps_Name, Language.Options_PrettierTimestamps_Description);
 
         if (Mutable.PrettierTimestamps)