feat(branding): replace ASCII fox banner with embedded image

HellionChat/SelfTests/FoxBannerTextureSmokeStep.cs

@@ -0,0 +1,47 @@
+using Dalamud.Bindings.ImGui;
+using Dalamud.Plugin.SelfTest;
+using HellionChat.Branding;
+
+namespace HellionChat.SelfTests;
+
+// Verifies the embedded fox-banner PNG decodes into a usable texture. The load
+// is async, so the step returns Waiting until Dalamud finishes the decode and
+// the self-test runner re-polls. A decode or resource error is a build defect
+// and fails the step hard. The resource lives in the DLL, it cannot be a
+// runtime miss.
+internal sealed class FoxBannerTextureSmokeStep : ISelfTestStep
+{
+    private readonly Plugin plugin;
+
+    public FoxBannerTextureSmokeStep(Plugin plugin)
+    {
+        this.plugin = plugin;
+    }
+
+    public string Name => "Hellion Chat - Fox banner texture smoke";
+
+    public SelfTestStepResult RunStep()
+    {
+        if (!FoxBannerTexture.Shared.TryGetWrap(out var wrap, out var ex))
+        {
+            if (ex is not null)
+            {
+                ImGui.Text($"Fox banner load failed: {ex.Message}");
+                return SelfTestStepResult.Fail;
+            }
+
+            ImGui.Text("Fox banner still loading...");
+            return SelfTestStepResult.Waiting;
+        }
+
+        if (wrap.Size.X <= 0 || wrap.Size.Y <= 0)
+        {
+            ImGui.Text($"Fox banner has degenerate size {wrap.Size}");
+            return SelfTestStepResult.Fail;
+        }
+
+        return SelfTestStepResult.Pass;
+    }
+
+    public void CleanUp() { }
+}