root cause: emitDecoratorMetadata reflected the third constructor parameter as Function and Nest attempted to resolve it
fix: optional HANDOFF_ID_FACTORY injection token, no production provider, preserving undefined -> crypto.randomUUID() default and unchanged positional construction
TDD: real CoordModule red at Function index [2], then green; test overrides only unrelated AuthGuard because its AUTH provider comes from AppModule's global AuthModule context
Closes#1145