enhance: make symlink display more visible with arrow

- Changed from: '🔗 _quarto.yml is symlink: config/_quarto-html.yml'
- Changed to:   '🔗 _quarto.yml → config/_quarto-html.yml'
- Arrow symbol makes the symlink relationship immediately clear
- More visual and concise display of what points to what

binder

@@ -119,7 +119,7 @@ class BookBinder:
         """Show simple symlink status"""
         if self.active_config.is_symlink():
             target = self.active_config.readlink()
-            console.print(f"[dim]🔗 _quarto.yml is symlink: {target}[/dim]")
+            console.print(f"[dim]🔗 _quarto.yml → {target}[/dim]")
         else:
             console.print(f"[dim]⚠️  _quarto.yml is NOT a symlink[/dim]")