fix(proxy): preserve https redirects behind Caddy and update H2 console hint

src/main/resources/application.properties

@@ -1,5 +1,6 @@
 spring.application.name=springboot-scaffold
 server.port=8083
+server.forward-headers-strategy=framework
 
 spring.profiles.active=${APP_PROFILE:learn}
 

src/main/resources/static/index.html

@@ -218,7 +218,7 @@
         </div>
         
         <footer>
-            <p>🍃 Spring Boot 学习脚手架 | <a href="/h2-console" target="_blank">H2 控制台</a> (JDBC: jdbc:h2:file:~/h2/springboot_scaffold, 用户: sa)</p>
+            <p>🍃 Spring Boot 学习脚手架 | <a href="/h2-console" target="_blank">H2 控制台</a> (learn 模式 JDBC: jdbc:h2:mem:springboot_scaffold_learn, 用户: sa)</p>
         </footer>
     </div>