refactor: 반환 타입 어노테이션 추가 — noun, predicator, core 모듈

[lovit]

대상

noun/lr.py

• LRNounExtractor.extract, predict
• 모듈 레벨 함수 다수: prepare_r_features, train_lrgraph, prepare_noun_candidates, longer_first_prediction, predict_single_noun, remove_ambiguous_features, check_r_features, extract_compounds_func, postprocessing

noun/postprocessing.py

• detaching_features, expand_suffix_nouns, check_N_is_NJ

core/lrgraph.py

• LRGraph.from_sents, iter_original_lr

predicator/

• EomiExtractor.extract, predict
• StemExtractor.extract
• PredicatorExtractor.train_extract, train, extract

[lovit]

PR #304 (feature/295)에서 해결되었습니다. refactor-2026에 병합 완료.