Proves the page half offline against synthetic pages — no browser, no live session — covering every extraction obstacle found on the real site (code without pre, shadow roots, unpromised indentation, the protocol-spec decoy), answer delivery (fill and click send, the Enter fallback, honest refusal when there is no composer), and the panel's collapse toggle.

## Before writing SPEC.md files

Read https://raw.githubusercontent.com/brillout/sdd/refs/heads/main/sdd.md
