v5.0.1

A new project comes with the language reference its coding agent needs.

New

• wf init writes AGENTS.md: the WebFluent language reference, in
  the file an AI coding agent reads before it changes a project, headed by
  the version of the wf that made it. An assistant asked to add a page
  writes this WebFluent — its flags, its slots, its checks — instead of
  guessing at a language it may never have seen. An older project can take
  the current one from the
  repository.

Changed

• AGENTS.md names wf init's copy and tests/ in the project
  layout, pins the Rust engine at version 5, says what moving from 4 to 5
  asks (wf check, quick fixes, lints and // wf-allow while a project
  catches up), and that a service call with an empty path parameter is not
  sent.

Tooling

• CI's check that every wf init template builds clean looked for 4.x's
  warning format, so it could no longer fail on a warning; it runs wf check --deny-warnings and requires the new AGENTS.md.

Full Changelog: v5.0.0...v5.0.1