docs(home): 홈 추천 신규 테이블 SQL 설명을 보강한다

docs/20260529_메인_홈_추천_API/create-new-entity-tables.sql

@@ -1,27 +1,27 @@
 create table recommendation_snapshot (
-    id bigint not null auto_increment,
-    created_at datetime(6) null,
-    updated_at datetime(6) null,
-    section_type varchar(50) not null,
-    target_id bigint not null,
-    score double not null,
-    snapshot_at datetime(6) not null,
-    random_tie_breaker double not null,
+    id bigint not null auto_increment comment 'ID',
+    section_type varchar(50) not null comment '섹션 타입',
+    target_id bigint not null comment '대상 ID',
+    score double not null comment '점수',
+    snapshot_at TIMESTAMP not null comment '스냅샷 시각',
+    random_tie_breaker double not null comment '랜덤 타이 브레이커',
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '생성 시각',
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '수정 시각',
     primary key (id),
     index idx_recommendation_snapshot_latest (section_type, snapshot_at, score, random_tie_breaker),
     index idx_recommendation_snapshot_target (section_type, target_id)
-);
+) comment '추천 스냅샷';
 
 create table creator_content_view_history (
-    id bigint not null auto_increment,
-    created_at datetime(6) null,
-    updated_at datetime(6) null,
-    member_id bigint not null,
-    content_id bigint not null,
-    genre_id bigint not null,
-    viewed_at datetime(6) not null,
+    id bigint not null auto_increment comment 'ID',
+    member_id bigint not null comment '회원 ID',
+    content_id bigint not null comment '콘텐츠 ID',
+    genre_id bigint not null comment '장르 ID',
+    viewed_at TIMESTAMP not null comment '시청 시각',
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '생성 시각',
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '수정 시각',
     primary key (id),
     index idx_creator_content_view_history_member_viewed (member_id, viewed_at),
     index idx_creator_content_view_history_content (content_id),
     index idx_creator_content_view_history_genre (genre_id)
-);
+) comment '크리에이터 콘텐츠 시청 이력';