Logs the perfect score on lesson 4 and sets priorities for what's next —
Perfekt/separable verb formation, accusative adjective endings, and the
still-untouched noun gender gap from lesson 2.
Targets the top gaps from the last diagnostic session — weil/dass/ob/wenn
verb-final order, multi-verb endings (modal + infinitive, Perfekt), a
dedicated ob vs. obwohl distinction, and accusative endings woven into
every drill sentence.
