Add example_system_prompts/ (prose, speeches, coding) and matching
example_user_prompts/ (four user prompts per domain, one file each so they
run directly via --prompt-file), plus a README mapping the pairs and the run
command against the default model.
Also refine the three system prompts: separate narrative register from
character speech and add a length default (prose); add a duration→word-count
rule, spoken-language guidance, a no-invented-evidence rule, and a salutation
note (speeches); fix the mangled numbered list and add a language default,
a no-invented-APIs rule, and clearer output ordering (coding).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
