Clears the owner's hard visual gate: a real gemini-2.5-flash reply rendered
through the actual app components (MessageBubble→Markdown/CodeBlock, DiffView)
via Expo web export, screenshotted in a real browser.
Per-surface verdict (all PASS, no app code changes needed):
- markdown: heading+bullets, high contrast light & dark
- code block: 430-char single line horizontally scrolls (scrolled-right reveals
the line END), not truncated/wrapped
- diff: fenced ```diff + native DiffView render +/- coloring and scroll
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>