feat: Automatic Chat Titles

[mkummer225]

Description

This PR adds automatic title generation for chat sessions. Currently it runs after the user submits their first chat (there's an opportunity for more robust logic added here). We piggy back off the user's currently selected model while limiting the maxTokens (response tokens) to 24; the baked-in prompt asks the model to reply with 4-12 words.

Currently this feature is enabled using the experimental config parameter: getChatTitles: boolean;

There appears to have been a prior effort to add this functionality via the disableSessionTitles config param (enabled by default then the user could opt-out). When this feature is ready to come out of experimental we should clean up this prior param (assuming I understood it's purpose correctly)

Checklist

• [x] The base branch of this PR is dev, rather than main
• [ ] The relevant docs, if any, have been updated or created

Screenshots

No visual changes were made; the titles are shown the same as before

Testing

Enable this feature by setting experimental.getChatTitles to true