Preserve SVG visuals in captured ChatGPT responses and improve capture fidelity.

Save ChatGPT responses after streaming finishes, including long-running answers. Choose all responses or only the last response. Improve capture cancellation, upload recovery, Mermaid completeness checks, and save-result feedback.

Improve ChatGPT capture, preserving Mermaid diagrams and formatted content. Update uploads for the current Reader document API.