Add settings page tabs and show env API keys with last four digits.

System settings now use the same CSS tab layout as env config; sensitive env fields display masked values from .env while keeping save-on-empty behavior.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/common/static/instance_settings_prefs.js

@@ -179,10 +179,24 @@
     } else {
       input = document.createElement("input");
       input.id = "env-f-" + field.key;
-      input.type = field.sensitive ? "password" : "text";
-      if (field.sensitive && field.has_value) {
-        input.placeholder = field.masked || "留空不修改";
+      input.type = "password";
+      input.autocomplete = "off";
+      if (field.sensitive) {
+        if (field.has_value) {
+          const cur = document.createElement("div");
+          cur.className = "env-sensitive-current muted";
+          const labelSpan = document.createElement("span");
+          labelSpan.textContent = "已配置 ";
+          const masked = document.createElement("span");
+          masked.className = "env-masked-value";
+          masked.textContent = field.masked || "";
+          cur.appendChild(labelSpan);
+          cur.appendChild(masked);
+          row.appendChild(cur);
+        }
+        input.placeholder = field.has_value ? "修改时填写新值，留空不修改" : "请输入";
       } else {
+        input.type = "text";
         input.value = field.current || field.default || "";
       }
     }