fix: improve onboarding auth UX

ui/src/ui/app.ts

@@ -186,6 +186,7 @@ export class ClawdisApp extends LitElement {
     this.syncThemeWithSettings();
     this.attachThemeListener();
     window.addEventListener("popstate", this.popStateHandler);
+    this.applySettingsFromUrl();
     this.connect();
     this.startNodesPolling();
   }
@@ -334,6 +335,20 @@ export class ClawdisApp extends LitElement {
     }
   }
 
+  private applySettingsFromUrl() {
+    if (!window.location.search) return;
+    const params = new URLSearchParams(window.location.search);
+    const token = params.get("token")?.trim();
+    if (!token) return;
+    if (!this.settings.token) {
+      this.applySettings({ ...this.settings, token });
+    }
+    params.delete("token");
+    const url = new URL(window.location.href);
+    url.search = params.toString();
+    window.history.replaceState({}, "", url.toString());
+  }
+
   setTab(next: Tab) {
     if (this.tab !== next) this.tab = next;
     void this.refreshActiveTab();