Feature Request: Add thumbs up/down feedback command

Summary

Add simple thumbs up/down feedback command to Claude Code, similar to GitHub Copilot's implementation in VS Code. This would allow users to quickly provide both positive and negative feedback on Claude's responses and actions.

Motivation

• Positive feedback is valuable: Currently, users primarily report issues/bugs, but there's no easy way to indicate when Claude performs exceptionally well
• Data for improvement: Both positive and negative signals help improve the AI's performance

Benefits

• Users can easily acknowledge when Claude "nails it"
• Provides balanced feedback data (not just problems)
• Minimal UI footprint
• Familiar interaction pattern from other AI tools

Reference Implementation

GitHub Copilot in VS Code provides a good example of this pattern working well in practice.