Chat attachments, in-chat profile updates & document fixes

✨ New Features

• Added support for attaching multiple files to a chat, with documents available directly in your conversation workflow.
• Added the ability to update your company profile from within a chat session.

🔧 Improvements

• Improved document version merging to better handle edits made across multiple steps of an agent workflow.
• Improved file extension handling to correctly preserve compound extensions (e.g. .tar.gz) during document operations.

🐞 Fixes

• Fixed an issue where version history was not correctly recorded when copying a document.