Add icons for Tokens, Commands, and Packages sections in the sidebar panel

[MUFFANUJ]

The sidebar panel sections currently lack distinct icons. Adding icons would improve visual scanability and UX.

Some of the suggestions:

• Commands → Play button — communicates "executable action"
• Tokens → Label/Tag — communicates "named identifier"
• Packages → Box or Globe — box for local packages, globe to hint at CDN/remote loading