[FEATURE] Allow renaming session titles after creation

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Summary
Currently, session titles in Claude Code are auto-generated from the first message and cannot be changed afterward. This makes it difficult to manage multiple sessions, especially when sessions span different phases or topics.

Requested Feature
Allow users (or agents) to rename session titles after creation, either via:

A UI option (right-click or edit button in the session list)
A CLI command (e.g., claude session rename <id> "new title")
An API/tool accessible to the agent itself during a session
Use Case
When managing multiple long-running sessions across projects, it's hard to distinguish which sessions are active, completed, or on hold — purely from auto-generated titles. Being able to rename sessions (e.g., adding ✅ for done, or clarifying the topic) would significantly improve session management UX.

Additional Context
It would also be valuable if agents could rename sessions programmatically during execution, so the session title can reflect the actual outcome rather than the initial prompt.

Proposed Solution

Summary
Currently, session titles in Claude Code are auto-generated from the first message and cannot be changed afterward. This makes it difficult to manage multiple sessions, especially when sessions span different phases or topics.

Requested Feature
Allow users (or agents) to rename session titles after creation, either via:

A UI option (right-click or edit button in the session list)
A CLI command (e.g., claude session rename <id> "new title")
An API/tool accessible to the agent itself during a session
Use Case
When managing multiple long-running sessions across projects, it's hard to distinguish which sessions are active, completed, or on hold — purely from auto-generated titles. Being able to rename sessions (e.g., adding ✅ for done, or clarifying the topic) would significantly improve session management UX.

Additional Context
It would also be valuable if agents could rename sessions programmatically during execution, so the session title can reflect the actual outcome rather than the initial prompt.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_