Add ability to rename sessions

[pgolawsk]

Feature Request: Add ability to rename sessions

Problem

Users who create multiple sessions per day cannot rename them to be identifiable. Session history becomes unmanageable.

Suggested Solution

Add "Rename Session" option via:

1. Right-click context menu on session in Agent Manager
2. Slash command like /rename [new name]
3. Edit icon next to session name

Use Case

I work on multiple tasks daily and need to name sessions (e.g., "ESPHome Debug", "React Fix") to find them easily in history.

[MiheevN]

It's strange that this hasn't happened yet. I'm also really looking forward to it.

[zprohub]

Really need it