Extends the checker to the module level `//!` docs, the tests, the
examples, and the non-Rust prose comments in the workflow, the manifests
and the shell and Python scripts.
All 180 comment blocks across apsis-core, apsis-units and apsis-math now
carry both languages. The checker confirms no mangled bytes and no English
word left inside a Chinese sentence, two mistakes that occurred while
writing them and are now caught mechanically.