feat: add git-glimpse logo to PR comment header

Adds a compressed logo asset (120x120px, 28KB) and embeds it inline
in the PR comment heading via raw.githubusercontent.com URL.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: DeDuckProject

assets/logo_square_small.png

@@ -79,8 +79,11 @@ function buildCommentBody(options: CommentOptions): string {
 
   const rerunSection = rerunUrl ? `\n\n[↺ Re-run demo](${rerunUrl})` : '';
 
+  const logoUrl =
+    'https://raw.githubusercontent.com/DeDuckProject/git-glimpse/main/assets/logo_square_small.png';
+
   return `${COMMENT_MARKER}
-## 🎬 UI Demo Preview
+## <img src="${logoUrl}" width="40" height="40" align="absmiddle" alt="git-glimpse logo" /> UI Demo Preview
 
 **Changes detected in**: ${changedFilesList}${moreFiles}