fix(toast): sticky toasts + improve update notification visibility (P5-40)

Add sticky?: boolean to ToastNotif — sticky toasts skip the 4s auto-dismiss
timer entirely, staying until the user clicks or manually dismisses. Sticky
toasts also use cyan accent/glow (vs orange for messages) and allow the body
to wrap rather than truncate, so longer action-oriented copy is fully readable.

Update the Tauri update toast to: sticky: true, ⬆ prefix on the title,
"Click to install and restart" as explicit call to action.

Fixes: auto-dismiss before user noticed it, no visual distinction from
a regular message notification.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/toast/LotusToastContainer.tsx

@@ -32,13 +32,14 @@ function ToastCard({ toast }: ToastCardProps) {
   const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   useEffect(() => {
+    if (toast.sticky) return;
     timerRef.current = setTimeout(() => {
       dismiss(toast.id);
     }, 4000);
     return () => {
       if (timerRef.current !== null) clearTimeout(timerRef.current);
     };
-  }, [dismiss, toast.id]);
+  }, [dismiss, toast.id, toast.sticky]);
 
   const handleCardClick = () => {
     if (toast.onClick) {
@@ -58,12 +59,14 @@ function ToastCard({ toast }: ToastCardProps) {
   const cardStyle: CSSProperties = {
     position: 'relative',
     background: 'var(--lt-bg-card)',
-    border: '1px solid var(--lt-border-color)',
+    border: toast.sticky
+      ? '1px solid var(--lt-accent-cyan-border)'
+      : '1px solid var(--lt-border-color)',
     borderRadius: '12px',
     padding: '12px 14px',
     minWidth: '280px',
     maxWidth: '340px',
-    boxShadow: 'var(--lt-box-glow-orange)',
+    boxShadow: toast.sticky ? 'var(--lt-box-glow-cyan)' : 'var(--lt-box-glow-orange)',
     cursor: 'pointer',
     animation: 'lotusToastIn 0.2s ease-out both',
     userSelect: 'none',
@@ -100,7 +103,7 @@ function ToastCard({ toast }: ToastCardProps) {
   };
 
   const nameStyle: CSSProperties = {
-    color: 'var(--lt-accent-orange)',
+    color: toast.sticky ? 'var(--lt-accent-cyan)' : 'var(--lt-accent-orange)',
     fontWeight: 600,
     fontSize: '0.85rem',
     overflow: 'hidden',
@@ -127,8 +130,9 @@ function ToastCard({ toast }: ToastCardProps) {
     fontSize: '0.82rem',
     margin: '4px 0 2px',
     overflow: 'hidden',
-    textOverflow: 'ellipsis',
-    whiteSpace: 'nowrap',
+    ...(toast.sticky
+      ? { whiteSpace: 'normal', lineHeight: 1.4 }
+      : { textOverflow: 'ellipsis', whiteSpace: 'nowrap' }),
   };
 
   const roomNameStyle: CSSProperties = {