feat(playbook): enhance SSH port detection and validation in K3s installation playbook

ansible/inventory/hosts.yml

@@ -2,10 +2,11 @@
 ---
 all:
   vars:
-    # SSH 配置 (初始连接使用密码)
+    # SSH 配置
     ansible_user: root
-    ansible_port: 2103
-    ansible_password: "{{ lookup('env', 'SSH_PASSWORD') }}"
+    # 默认端口，首次安装时使用22，后续会被动态覆盖
+    ansible_port: 22
+    ansible_password: "{{ lookup('env', 'SSH_PASSWORD') | default(omit, true) }}"
 
     # SSH 安全配置
     ssh_new_port: 2103