Cheap filename-only filter the detector pass uses to skip #detect on files the detector cannot possibly match. The default true preserves prior behavior (every detector runs on every file). Override with the same predicate the body of #detect starts with — e.g., filename.ends_with?(".py") for a Python framework detector — so the detector loop avoids the #detect dispatch on files outside the detector's language.

On large codebases (saleor's 4255 .py files) this lifts ~100 virtual #detect calls per file out of the hot loop because most detectors' inner first-line is exactly this kind of cheap filename check.

Pocketbase apps are full Go programs that import the framework's own tools/router package. The framework repo itself self-references via the same path so the marker works whether you're scanning a user app or the upstream.