Less waiting after conversations, plus fixes for chat errors, pasted images, and agent branding

We've reduced delays after a conversation ends. Results are prepared sooner, and participants can move on to the next page sooner.

• Pasting an image into chat now attaches it once, instead of adding two copies.
• Fixed an error that sometimes interrupted text conversations, agent design, and analysis sessions after a reply appeared.
• When you remove a workspace member, their agents move to the workspace owner. The name and picture shown in those conversations now stay the same.