chore: lib-kafka 버전을 1.0.1로 업데이트

- 0.5.0 → 1.0.1
- NotificationType 표준명 정리, resolveTitle 헬퍼 추가 반영

docs: Kafka 문서를 통합하고 최신 구조로 정리

feat: Kafka 계약 상수와 notification helper 추가

Add centralized Kafka contract constants and notification helpers

Fix UsageRealtimePayload contract regression

Restructure Kafka library packages and add event publisher contracts

feat: Add serialization method

fix: change tag README

chore: rename to lib-kafka and bump coordinates to v0.2.0

chore: stabilize jitpack publish config and refresh readme