feat(desktop): "Start minimized" setting under Launch on login (cinny-desktop #3)

Shown only while Launch on login is on, and only when the native side
answers `get_start_minimized` (older desktop builds just don't show it).
Toggling calls `set_start_minimized`.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/settings/general/General.tsx

@@ -161,11 +161,19 @@ function DesktopChromeSetting() {
  */
 function AutostartSetting() {
   const [enabled, setEnabled] = useState(false);
+  // [cinny-desktop #3] null until the native side answers (older builds don't
+  // have the command, so the switch just stays hidden there).
+  const [startMinimized, setStartMinimized] = useState<boolean | null>(null);
 
   useEffect(() => {
     tauriInvoke()?.('plugin:autostart|is_enabled')
       .then((value) => setEnabled(value === true))
       .catch(() => undefined);
+    tauriInvoke()?.('get_start_minimized')
+      .then((value) => {
+        if (typeof value === 'boolean') setStartMinimized(value);
+      })
+      .catch(() => undefined);
   }, []);
 
   const handleChange = (value: boolean) => {
@@ -173,6 +181,11 @@ function AutostartSetting() {
     setEnabled(value);
   };
 
+  const handleStartMinimized = (value: boolean) => {
+    invokeTauri('set_start_minimized', { value });
+    setStartMinimized(value);
+  };
+
   if (!isTauriEnv()) return null;
   return (
     <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column">
@@ -181,6 +194,15 @@ function AutostartSetting() {
         description="Start Lotus Chat automatically when you sign in to your computer."
         after={<Switch variant="Primary" value={enabled} onChange={handleChange} />}
       />
+      {enabled && startMinimized !== null && (
+        <SettingTile
+          title="Start minimized"
+          description="When it starts at login, keep Lotus Chat in the system tray instead of opening the window. Notifications still arrive; click the tray icon to open it."
+          after={
+            <Switch variant="Primary" value={startMinimized} onChange={handleStartMinimized} />
+          }
+        />
+      )}
     </SequenceCard>
   );
 }