[Feature Request] Highlight syntax spans that trigger permission prompts in Bash commands

Bug Description
Title: Highlight the specific syntax span that triggers a permission prompt

When a Bash command is flagged for permission (e.g. "Contains shell syntax (array) that cannot be statically analyzed"), the prompt shows the full command but doesn't indicate where in the command the offending construct is. For multi-line or long commands, this means the user has to manually scan the whole command to find the part that triggered the prompt

Highlight (e.g. bold/underline/color) the specific span of syntax responsible for the "cannot be statically analyzed" (or other permission-triggering) determination, directly in the rendered command preview

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.226
• Feedback ID: 2b1664bc-d606-421f-8fa1-b1009c983fb9