feat: add option to disable update checker

Add a new setting in User Profile > Settings to disable automatic
update checking on startup and dashboard.

- Adds 'Disable Update Check' toggle in profile settings
- Skips GitHub API calls when disabled (reduces network requests)
- Works for both web app and Electron client

Fixes Termix-SSH/Support#410

src/ui/desktop/user/UserProfile.tsx

@@ -133,6 +133,9 @@ export function UserProfile({
     const saved = localStorage.getItem("showHostTags");
     return saved !== null ? saved === "true" : true;
   });
+  const [disableUpdateCheck, setDisableUpdateCheck] = useState<boolean>(
+    localStorage.getItem("disableUpdateCheck") === "true",
+  );
   const [userRoles, setUserRoles] = useState<UserRole[]>([]);
 
   useEffect(() => {
@@ -212,6 +215,11 @@ export function UserProfile({
     window.dispatchEvent(new Event("showHostTagsChanged"));
   };
 
+  const handleDisableUpdateCheckToggle = (enabled: boolean) => {
+    setDisableUpdateCheck(enabled);
+    localStorage.setItem("disableUpdateCheck", enabled.toString());
+  };
+
   const handleDeleteAccount = async (e: React.FormEvent) => {
     e.preventDefault();
     setDeleteLoading(true);
@@ -613,6 +621,28 @@ export function UserProfile({
                     </div>
                   </div>
                 </div>
+
+                <div className="rounded-lg border-2 border-edge bg-elevated p-4">
+                  <h3 className="text-lg font-semibold mb-4">
+                    {t("profile.updateSettings")}
+                  </h3>
+                  <div className="space-y-4">
+                    <div className="flex items-center justify-between">
+                      <div>
+                        <Label className="text-foreground-secondary">
+                          {t("profile.disableUpdateCheck")}
+                        </Label>
+                        <p className="text-sm text-muted-foreground mt-1">
+                          {t("profile.disableUpdateCheckDesc")}
+                        </p>
+                      </div>
+                      <Switch
+                        checked={disableUpdateCheck}
+                        onCheckedChange={handleDisableUpdateCheckToggle}
+                      />
+                    </div>
+                  </div>
+                </div>
               </TabsContent>
 
               <TabsContent value="security" className="space-y-4">