Feature request: Auto-generate session name from conversation content (like Gemini)

Feature Request

Summary

Automatically generate and update session names based on conversation content, similar to how Google Gemini auto-titles conversations.

Current Behavior

• Session names can only be set manually via --name flag at startup or /name slash command during a session.
• There is no way to programmatically set the session name from within tools/hooks.

Desired Behavior

• After the first few exchanges, automatically generate a concise summary title for the session.
• Optionally update the title as the conversation topic evolves.
• This would make it much easier to find and distinguish past sessions in claude --resume or session history.

Motivation

• Users coming from Gemini / ChatGPT expect auto-titling as a baseline UX feature.
• Manually naming every session is friction that most users skip, making session history less useful.
• The /name command exists but is not accessible from tools or hooks, so even workarounds are not feasible.

Possible Approaches

1. Built-in auto-titling after the first user message or assistant response.
2. Expose session name API to hooks/tools so users can build their own auto-naming.
3. Both.