v0.4.0

• Refresh deps (spellweaver, credo, dialyxir, ex_doc, igniter).
• Pass --strict to credo in default aliases so the strict mode (already set
  in the generated .credo.exs) is obvious at the call site.
• Fill out the CI template to match mix check: hex.audit, credo --strict,
  spellweaver.check, and dialyzer now run on the lint matrix row, and the
  build cache covers _build so the dialyzer PLT survives between runs.