fix: Prevent crash if a preview card does not have an author

app/src/main/java/app/pachli/view/PreviewCardView.kt

@@ -86,7 +86,7 @@ class PreviewCardView @JvmOverloads constructor(
 
         when {
             card.description.isNotBlank() -> card.description
-            card.authorName.isNotBlank() -> card.authorName
+            card.authorName.orEmpty().isNotBlank() -> card.authorName
             else -> null
         }?.let { cardDescription.text = it } ?: cardDescription.hide()
 

core/network/src/main/kotlin/app/pachli/core/network/model/TrendsLink.kt

@@ -41,7 +41,7 @@ interface PreviewCard {
     val title: String
     val description: String
     val kind: PreviewCardKind
-    val authorName: String
+    val authorName: String? // Not supposed to be null, per API, but seen null in the wild
     val authorUrl: String
     val providerName: String
     val providerUrl: String