Coarse‑grained auto‑export vs. manual module‑info.java for Ceylon JPMS
Goal: enable fine‑grained control over which Ceylon packages are exported as JPMS modules when the module is consumed from Java 9+ without leaking internal APIs. Constraint: the Ceylon 1.3.4 compiler generates a module‑info.class that exports every package containing a shared declaration, treating internal shared packages as public exports; there is no langu