refactor: 网关数据库驱动由 MySQL 切换为 PostgreSQL

- pom：mysql-connector-j 换为 postgresql。
- application(.prod).yml：JDBC URL 改为 jdbc:postgresql://，默认账号改 root。
- 网关只连主库 iot_platform（open_client / open_webhook / open_api_log），不连业务库，
  无需感知后端的共享业务库与租户插件。

pom.xml

@@ -56,10 +56,10 @@
             <version>${mybatis-plus.version}</version>
         </dependency>
 
-        <!-- MySQL 驱动 -->
+        <!-- PostgreSQL 驱动 -->
         <dependency>
-            <groupId>com.mysql</groupId>
-            <artifactId>mysql-connector-j</artifactId>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
             <scope>runtime</scope>
         </dependency>
 

src/main/resources/application-prod.yml

@@ -3,8 +3,8 @@ server:
 
 spring:
   datasource:
-    url: ${DB_URL:jdbc:mysql://127.0.0.1:14406/iot_platform?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true}
-    username: ${DB_USERNAME:iot_app}
+    url: ${DB_URL:jdbc:postgresql://127.0.0.1:5432/iot_platform}
+    username: ${DB_USERNAME:root}
     password: ${DB_PASSWORD:}
 
 gateway:

src/main/resources/application.yml

@@ -6,9 +6,9 @@ spring:
     name: iot-open-gateway
 
   datasource:
-    driver-class-name: com.mysql.cj.jdbc.Driver
-    url: ${DB_URL:jdbc:mysql://127.0.0.1:3306/iot_platform?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true}
-    username: ${DB_USERNAME:iot_app}
+    driver-class-name: org.postgresql.Driver
+    url: ${DB_URL:jdbc:postgresql://127.0.0.1:5432/iot_platform}
+    username: ${DB_USERNAME:root}
     password: ${DB_PASSWORD:}
 
 mybatis-plus: