#jni_interface, #objc_class, #objc_protocol, #swift_class,
#swift_struct, #swift_protocol — each with the same body grammar as
#jni_class. Today the lexer doesn't recognise any of these directives
and the parser errors at the first one (`#jni_interface`). The
make-green follow-up adds the six lexer tokens and refactors
`JniClassDecl` into `ForeignClassDecl` with a `runtime` discriminator
so all seven forms share one AST shape and one parser path.
