Gemini WebChat release.
- Add Gemini WebChat as a built-in web model provider.
- Use text-context mode for Gemini so it can read the current paper without requiring the fragile PDF attachment flow.
- Fix Gemini answer capture so PaperDock keeps the generated answer instead of showing the submitted prompt or paper context.
- Restore Markdown structure for compact Gemini numbered summaries, limitations, learning advice, and follow-up questions.
- Preserve already generated WebChat content when a Gemini stream or page connection disconnects.
- Add Gemini WebChat contract and stream parser tests.