Add NIP-05 badges, hashtag pages, keyword muting, suggestion dismissal, notification poller

- Article cover: aspect-video replaces max-h-72 for consistent 16:9
- NIP-05 verification badge on note cards with 1-hour TTL cache
- Dedicated hashtag feed pages (clicking #tag opens live feed, not search)
- Keyword muting: word-boundary matching, applied across all feed views
- Follow suggestion dismissal: persistent "don't suggest again" per person
- Background notification poller (60s): mentions, zaps, new followers
- All notification types independently toggleable in settings
- Centralized notification firing (removed inline store notifications)

src/components/article/ArticleView.tsx

@@ -276,7 +276,7 @@ export function ArticleView() {
                   <img
                     src={image}
                     alt=""
-                    className="w-full max-h-72 object-cover rounded-sm"
+                    className="w-full aspect-video object-cover rounded-sm"
                     onError={(e) => { (e.target as HTMLImageElement).style.display = "none"; }}
                   />
                 </div>