feat(settings): add LivePreviewPanel skeleton

HellionChat/Ui/Components/Settings/LivePreviewPanel.cs

@@ -0,0 +1,88 @@
+using System.Numerics;
+using System.Threading;
+using Dalamud.Bindings.ImGui;
+using Dalamud.Interface.Utility.Raii;
+using HellionChat.Themes;
+using HellionChat.Ui.StyleEngine;
+
+namespace HellionChat.Ui.Components.Settings;
+
+internal sealed class LivePreviewPanel : IDisposable
+{
+    // Static counter for S5 reload-stress verification: after 10 reloads the
+    // counter must read 0 (plugin disabled) or 1 (plugin enabled). Anything
+    // higher signals a Dispose skip and a subscriber leak against ThemeRegistry.
+    internal static int InstanceCount;
+
+    private readonly ThemeRegistry _themes;
+    private readonly TokenResolver _resolver;
+
+    public LivePreviewPanel(ThemeRegistry themes, TokenResolver resolver)
+    {
+        _themes = themes;
+        _resolver = resolver;
+        _themes.OnEditingBufferChanged += OnBufferChanged;
+        Interlocked.Increment(ref InstanceCount);
+    }
+
+    public void Dispose()
+    {
+        _themes.OnEditingBufferChanged -= OnBufferChanged;
+        Interlocked.Decrement(ref InstanceCount);
+    }
+
+    private void OnBufferChanged()
+    {
+        // Visual repaint already runs per frame via Draw(); hook reserved for
+        // future telemetry or invalidation. Keep empty in v1.7.0.
+    }
+
+    public void Draw()
+    {
+        using var child = ImRaii.Child("##settings-live-preview", new Vector2(280, 0), true);
+        if (!child.Success)
+        {
+            return;
+        }
+
+        var theme = _themes.EditingThemeBuffer ?? _themes.Active;
+
+        DrawBrandBar(theme);
+        DrawHonorificHeader(theme);
+        DrawSidebar(theme);
+        DrawMessageList(theme);
+        DrawInputBar(theme);
+        DrawStatusBar(theme);
+    }
+
+    private void DrawBrandBar(Theme theme)
+    {
+        // Mini gradient: PrimaryDark → Primary → PrimaryLight → PrimaryGlow.
+        // Implementation lands in next sub-step.
+    }
+
+    private void DrawHonorificHeader(Theme theme)
+    {
+        // Crown + Brackets-Title in Identity. Implementation in next sub-step.
+    }
+
+    private void DrawSidebar(Theme theme)
+    {
+        // 3 channel rows. Implementation in next sub-step.
+    }
+
+    private void DrawMessageList(Theme theme)
+    {
+        // 4 mock messages. Implementation in next sub-step.
+    }
+
+    private void DrawInputBar(Theme theme)
+    {
+        // Pill + text + cog. Implementation in next sub-step.
+    }
+
+    private void DrawStatusBar(Theme theme)
+    {
+        // Status icons. Implementation in next sub-step.
+    }
+}