Tab Beautification

We've improved the UI for chat tabs:

We also now save chat history, so you can restore previous tabs:

You can also now edit branch names in the top bar:

Improvements

• Window size and location now persists across restart
• Wider chats on large screens

Fixes

• File names will always be visible when expanding tool calls
• Prevent enter key from closing alert dialogs
• Fix mutations causing UI lag
• Fix drag regions in the top bar