Feature Request: Message threading, reply anchoring, and reactions

When working on long technical conversations in Claude Code (e.g. debugging, multi-step implementations, security reviews), it becomes hard to reference, revisit, or signal feedback on a specific earlier response without scrolling through the entire conversation.

Requested features:

1. Message threading / reply anchoring
Allow users to reply to or anchor a specific message — similar to Slack threads — so they can:

• Jump back to a specific response
• Continue a sub-topic from an earlier point without losing context
• Reference a specific response when asking a follow-up question

2. Message reactions
Allow users to react to individual messages with emoji reactions — similar to Slack/GitHub — so they can:

• Quickly mark a response as helpful ✅
• Flag a response as incorrect or needs revisiting ❌
• Bookmark key responses 🔖 without interrupting the conversation flow

Use case example:
During a long session covering multiple topics (e.g. CI changes, Docker changes, local dev hooks), the user wants to:

• Revisit a specific earlier response about CI testing steps without losing current context
• Mark the final agreed approach on a specific response without sending a new message

Expected behaviour:

• Each message has a reply/anchor option and a reaction bar on hover
• Clicking reply includes the referenced message as context
• Reactions are visible inline
• Reacted/threaded messages can be filtered or jumped to

Current behaviour:
No way to reference, navigate to, or react to a specific earlier message — users must scroll manually and type follow-up messages to acknowledge or flag responses.

Environment:

• Claude Code VSCode extension / CLI
• Platform: macOS