The instruction asks for "ADVICE:", but the model writes "**ADVICE:**",
"## ADVICE:" or puts it in a code block. The extraction has to cope,
because leftover markdown in the advice is visible to the brewer.
The marker is now matched case-insensitively and with the decoration the
model puts around it, and the leftover formatting is stripped.
plain marker -> 'Warm it to 20C and wait.'
bold marker -> 'Warm it to 20C and wait.'
in a code block -> 'Warm it to 20C and wait.'
marker mid-text -> 'Warm it to 20C and wait.'
markdown heading -> 'Warm it to 20C and wait.'
lowercase marker -> 'Warm it to 20C and wait.'
no marker -> 'Warm it to 20C and wait.'
bold + code block -> 'Warm it to 20C and wait.'
182 tests (up from 181).