Swift Api Design Guidelines

Enforces the official Swift API Design Guidelines with decision tables and concrete rules for argument labels, mutating/nonmutating pairs, and side-effect naming. You'll want this when you're stuck on whether to use `sorted()` or `sorting()`, when to omit the first argument label, or how to name a Boolean property so it reads like an assertion. The prepositional phrase rule and grammatical phrase rule are spelled out with examples, and there's a clear -ed/-ing suffix guide that explains why it's `sorted()` but `strippingNewlines()`. Targets Swift 6.3 and stays focused on naming conventions, routing type-system questions to other skills. Most useful during API design reviews or when refactoring for call-site clarity.