fix: 使用 database_init.sql 初始化数据库（含管理员账号和系统配置）

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.yml

@@ -12,7 +12,7 @@ services:
       - "${DB_PORT_EXTERNAL:-5433}:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
-      - ./backend/aigcspace_clean.sql:/docker-entrypoint-initdb.d/init.sql
+      - ./backend/database_init.sql:/docker-entrypoint-initdb.d/init.sql
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U ${DB_USER:-postgres}"]
       interval: 10s