fix: 恢复 V1 原样，site_type 改动迁移到 V5

- V1: 恢复到原始 DEFAULT 'private' + 原始注释
- V5: ALTER TABLE sites MODIFY site_type DEFAULT 'unknown'
- 彻底解决 Flyway checksum 冲突，不改 flyway_schema_history

par-api/src/main/resources/application.yml

@@ -31,7 +31,6 @@ spring:
     locations: classpath:db/migration
     baseline-on-migrate: true
     baseline-version: 0
-    validate-on-migrate: false
 
 mybatis-plus:
   configuration: