fix(notifications): show thumbnail image in overlay mined-card notificat

- Share generated notification icon between overlay and system notification paths
- Add `image` field to OverlayNotificationPayload; render as IMG with has-image layout
- Widen overlay stack to 420px; enlarge card padding and min-height for image variant
- Show OSD message after successful anilist retry when attempt key already handled

src/types/notification.ts

@@ -23,6 +23,7 @@ export interface OverlayNotificationPayload {
   id?: string;
   title: string;
   body?: string;
+  image?: string;
   variant?: OverlayNotificationVariant;
   position?: OverlayNotificationPosition;
   persistent?: boolean;