Ability to organize loose chats

### Feature summary

In the general chats area it would be nice to group some chats into a "folder" or maybe with a tag.

### What problem are you trying to solve?

Sometimes I start a chat that doesnt belong to a project at the moment. I then go down a rabbit hole and explore an entire topic. I may spin up other chats or fork because I am exploring something different but related to the original chat.
In hindsight I should have created a temp folder and then started a project then kept my chats in there, but I had no idea it would spiral into something so big.

### Proposed solution

It would be nice to be able to drag some of those chats into a folder that existed only in the github app after the fact. or possible the ability for me to create a new folder on my machine then create a project on that folder and then drag those chats into that folder.
An example would be " I am trying to figure out an authentication approach, I have a few ideas but need to dig".... I end up learning more about the protocol and philosophy, I spin up other chats to explore deeper into particular systems. There is a ton of good information in them but I am worried they will get buried as I ask about other "one-off" questions. It would be cool to be able to group or tag them or slide them into a new project.

### Workflow impact

Individual users, and organization. Organization is the name of the game here. If I learn stuff through the chats but then forget and need to reference them but cant find them then what was the point.

### Installation context

_No response_

### Additional context

_No response_

No files, tests, or entry points are identified in the issue, so begin by clarifying whether the intended behavior is folders, tags, or moving chats into projects. Done would require an agreed interaction and complete organization workflow for loose chats, including how users create groups and find chats again.

索引モデルが issue の本文から書いたものです。