Two bugs fixed:
1. TS Generator: Enum values in guard expressions and emit fields
were prefixed with the wrong enum name (always using the state
enum). Now builds a value→enumName map from enumMap and passes it
to rewriteExpr so each value gets its correct enum prefix
(e.g., ArtifactKind.Provenance instead of CompilerPhase.Provenance).
2. Parser: emit field splitting used simple comma-split which broke
quoted strings containing commas (e.g., join(outputDir, ".prov.jsonld")).
Now respects quotes and parentheses when splitting.
Also: join() calls now generate path.join() instead of String.join(),
and generated TS includes 'import path from path'.
Fixes: marcus/engineering#9
