Add rich text links, language filter, and domain deny feature

- Use labeled links (Article · Audio) instead of raw URLs in posts
- Add language filter dropdown to dashboard with toggle selection
- Auto-deny feeds with no language on discovery
- Add deny/undeny buttons for domains to block crawling
- Denied domains set feeds to dead status, preventing future checks

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

feed.go

@@ -178,9 +178,14 @@ type Feed struct {
 // saveFeed stores a feed in PostgreSQL
 func (c *Crawler) saveFeed(feed *Feed) error {
 	// Default publishStatus to "held" if not set
+	// Auto-deny feeds with no language specified
 	publishStatus := feed.PublishStatus
 	if publishStatus == "" {
-		publishStatus = "held"
+		if feed.Language == "" {
+			publishStatus = "deny"
+		} else {
+			publishStatus = "held"
+		}
 	}
 
 	_, err := c.db.Exec(`