Centralised URL builders for the catalog and lesson pages. Pages and
components import these instead of concatenating URL strings, so
future routing changes happen in one place.
Parameters
course: CourseRef
Returns string
Remarks
/courses/<slug> itself has no page: every course route names what it
shows (/progress, /about, /modules/...).
Centralised URL builders for the catalog and lesson pages. Pages and components import these instead of concatenating URL strings, so future routing changes happen in one place.