Fix settings loading and use 2-column card layout.

Merge Flask GET/POST routes, refresh prefs on tab revisit after preload, and reorganize system settings into separate cards.

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

lib/common/static/instance_embed.js

@@ -117,6 +117,16 @@
         }
       }
     }
+    if (revisit && (tab === "settings" || tab === "env_config")) {
+      if (global.InstanceSettingsPrefs) {
+        if (tab === "settings" && typeof global.InstanceSettingsPrefs.loadDisplayPrefsForm === "function") {
+          global.InstanceSettingsPrefs.loadDisplayPrefsForm();
+        }
+        if (tab === "env_config" && typeof global.InstanceSettingsPrefs.loadEnvConfig === "function") {
+          global.InstanceSettingsPrefs.loadEnvConfig();
+        }
+      }
+    }
     if (!revisit) {
       if (typeof global.refreshAccountSnapshot === "function") {
         global.refreshAccountSnapshot({ silent: true });
@@ -296,6 +306,7 @@
     }
     if (revisit) {
       document.body.setAttribute("data-page", tab);
+      runPageInit(tab, { revisit: true });
       return;
     }
     runPageInit(tab, { revisit: false });