Feature request: line numbers on conversation messages

Feature Request

Add sequential line/message numbers to the left of each input/output block in the Claude Code chat flow (next to the colored dots).

Use Case

When working in long, intensive sessions with Claude Code, it's hard to track and reference specific points in the conversation. Line numbers would make it easy to:

• Quickly reference a specific exchange ("check what happened at message 47")
• Track progress through a session
• Keep up with fast-moving autonomous work

Current Behavior

Messages have colored dots (user vs assistant) but no numbering.

Proposed Behavior

Add a sequential number (1, 2, 3...) to the left of each message's indicator dot. Could be subtle/dimmed to not clutter the UI.