feat(branding): embed Hellion Forge fox ASCII signature

Ship two ASCII variants as embedded resources under HellionChat.Branding:

- fox-banner.txt — full silhouette with "Hellion Forge" set inside the
  body, rendered in the first-run wizard and the Settings Information
  tab as a folded "about the makers" anchor
- fox-mini.txt — compact fox-head + curly-tail used by the DI-logger
  bootstrap banner

A small HellionForgeAscii helper lazy-loads both strings; the wizard
and information-tab render them in a collapsed TreeNode using the
UiBuilder MonoFontHandle so the stipple-art lands pixel-aligned.

Both art files are self-made (Julia Moon, free to use) and travel with
the plugin DLL so a partial deploy can't lose them.

HellionChat/Branding/HellionForgeAscii.cs

@@ -0,0 +1,36 @@
+namespace HellionChat.Branding;
+
+// Lazy-loaded provenance art that ships embedded with the DLL. Two
+// variants:
+//
+//   - FoxBanner: the full-size silhouette with "Hellion Forge" inside
+//     the body — rendered in the first-run wizard and the Information
+//     tab as a small "about the makers" anchor.
+//   - FoxMini: the four-line fox-head + curly-tail that gets stitched
+//     into the DI-logger bootstrap line so an xllog reader sees the
+//     same signature on every plugin load.
+//
+// Both files live as embedded resources under HellionChat.Branding.* so
+// the plugin DLL is self-contained — no on-disk asset lookup that could
+// silently miss after a partial deploy.
+internal static class HellionForgeAscii
+{
+    private static string? _foxBanner;
+    private static string? _foxMini;
+
+    public static string FoxBanner => _foxBanner ??= Load("HellionChat.Branding.fox-banner.txt");
+
+    public static string FoxMini => _foxMini ??= Load("HellionChat.Branding.fox-mini.txt");
+
+    private static string Load(string resourceName)
+    {
+        using var stream = typeof(HellionForgeAscii).Assembly.GetManifestResourceStream(
+            resourceName
+        );
+        if (stream is null)
+            return string.Empty;
+
+        using var reader = new StreamReader(stream);
+        return reader.ReadToEnd();
+    }
+}