[Feature Request] Programmatic session title / rename API

Bug Description
Feature request: programmatic session title / rename API

Today there's no way to set or rename a Claude Code session title from inside the session. The VSCode extension auto-generates titles from conversation content, and they're often unhelpful for later search ("Untitled", generic summaries, etc.). I currently rename sessions by hand to prefix them with a ticket ID (e.g. [BLZ-14683] ...) so I can find them later.

I'd love any one of the following:

1. A slash command — /rename-session "<title>" that updates the current session's title.
2. A hook output field — let SessionStart / UserPromptSubmit / PostToolUse hooks return JSON like { "sessionMetadata": { "title": "..." } } to set the title programmatically.
3. A skill-accessible API / tool — so a skill (e.g. my investigate-issue skill) can set the title as part of its workflow when it has the relevant context (ticket ID, bug summary, etc.).

Use case: I have skills that operate on Linear tickets and always know the ticket ID up front. Being able to auto-title the session [BLZ-1234] <summary> would make my session history searchable without manual renaming.

Bonus: a settings.json option for a default title template (e.g. based on git branch — my branches are already named blz-14683-...) would solve the same problem more generally.

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.104
• Feedback ID: f7be39f6-5f21-4ef0-bbed-241489343dd2

Errors

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