fact-checking-by-executionlisted

# Fact-checking by execution **The only admissible evidence for an operation claim is having run it.** This skill owns whether a claim is true. It does not own how the claim is worded, how long the page runs, or where it lives. Documentation states how something behaves now. Every other source — your memory, a neighbouring module's README, the shape of the config file, what the function name implies — is a guess with good posture. Guesses are exactly as likely to be right as the last time the code moved, and nothing tells you when that was. This procedure is mandatory for every new document, and for every new paragraph that claims an operation, command, default, error, or platform difference. ## Procedure 1. **Run every claimed operation against the current checkout.** Execute each command, configuration snippet, and example **exactly as the document will show it** — not a variant you know works. Write down only what you observed, including exact output, warnings, and failure modes. 2. **Record observations, not expectations.** If the output surprised you, the surprise is the finding. Quote it. 3. **Delete what you could not reproduce.** Never carry a command, field, default value, or behavior forward from memory, from analogy, or from a neighbouring project's documentation. **When a claim fails to reproduce, fix the claim — not the test.** The failure just told you something true. 4. **Check existing pages against the current default branch.** Before revising a pre-