Feature request: Organize and group past sessions

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

Title: Feature request: Organize and group past sessions
Body:
When using /resume, the session list grows quickly and becomes hard to navigate.
It would be helpful to have ways to organize sessions, such as:

Folders or tags for grouping related sessions
Renaming sessions with custom titles
Archiving or deleting old sessions
Search/filter by keyword
This would make it much easier to find and manage past conversations, especially for users who work on multiple projects.　日本語で確認したいので翻訳して

Proposed Solution

Title:

Feature request: Organize and group past sessions

Body:

When using /resume, the session list grows quickly and becomes hard to navigate.

It would be helpful to have ways to organize sessions, such as:

Folders or tags for grouping related sessions
Renaming sessions with custom titles
Archiving or deleting old sessions
Search/filter by keyword
This would make it much easier to find and manage past conversations, especially for users who work on multiple projects.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_