Make tool description more prominent in approval dialog

When a Bash command is shown for approval, the description field appears as small grey text below the raw command. For non-technical users, the description is far more useful than the raw command.

Request: Make the description larger/bolder, or show it above the command, so users can quickly understand what's being approved without parsing shell syntax.

Current behavior:

• Raw command dominates the prompt
• Description is tiny grey text below, easy to miss

Suggested improvement:

• Show description prominently above the command (larger font, bold)
• Optionally collapse the raw command behind a "show details" toggle