fix(settings): show SSH password and passphrase inputs (#609)

The SSH configuration form only asked for a password after a failed Test Connection, so choosing Password showed nothing but a "Save password" checkbox. It now shows a Password row, or a Passphrase row for key pairs.

The typed secret is staged with the other settings changes: it is written on Apply / OK and discarded on Cancel or Reset, and Test Connection uses it without storing it. An emptied field leaves the stored secret alone. Deployment, run target and data source forms have their own secret inputs and are unchanged.

src/platform/locales/text/zh.json

@@ -1423,6 +1423,7 @@
   "Language server JDK": "语言服务器 JDK",
   "Password": "密码",
   "Password:": "密码：",
+  "Password already stored": "已存储密码",
   "Paste": "粘贴",
   "Paste on middle mouse button click": "点击鼠标中键时粘贴",
   "Patch copied to the clipboard": "补丁已复制到剪贴板",
@@ -2757,6 +2758,7 @@
   "Startup script:": "启动脚本：",
   "Runs on every new connection, before any other statement.": "在每个新连接上、任何其他语句之前运行。",
   "Passphrase:": "密码短语：",
+  "Passphrase": "密码短语",
   "Mode:": "模式：",
   "CA file:": "CA 文件：",
   "System roots when empty": "为空时使用系统根证书",