Function write_compiled_file 

pub fn write_compiled_file(file: &CompiledFile, dir: &Path) -> Result<(), Error>

Write a single CompiledFile under dir, map-aware: a .bynk-sourced file gets a sibling .ts.map and a //# sourceMappingURL trailer (slice 1, ADR 0103); a file with no map is written verbatim. Shared by write_output and bynkc test’s output loops, so every disk-writing path emits maps uniformly (slice 2 — bynkc test --inspect runs the emitted .ts directly and needs the maps on disk). The trailer lives only on the on-disk artefact; the in-memory file.typescript stays trailer-free, so golden comparisons are unaffected. The map name appends .map to the output file name.