Fix catalog refresh: handle null fields in AppImageHub feed JSON

src/core/catalog.rs

@@ -152,17 +152,17 @@ fn fetch_appimage_hub() -> Result<Vec<CatalogApp>, CatalogError> {
     let apps: Vec<CatalogApp> = feed.items.into_iter().filter_map(|item| {
         // AppImageHub items need at least a name and a link
         let name = item.name?;
-        let download_url = item.links.into_iter()
+        let download_url = item.links.unwrap_or_default().into_iter()
             .find(|l| l.r#type == "Download")
             .map(|l| l.url)?;
 
         Some(CatalogApp {
             name,
             description: item.description,
-            categories: item.categories.unwrap_or_default(),
+            categories: item.categories.unwrap_or_default().into_iter().flatten().collect(),
             latest_version: None,
             download_url,
-            icon_url: item.icons.and_then(|icons| icons.into_iter().next()),
+            icon_url: item.icons.and_then(|icons| icons.into_iter().flatten().next()),
             homepage: item.authors.and_then(|a| {
                 let first = a.into_iter().next()?;
                 if let Some(ref author_name) = first.name {
@@ -237,10 +237,10 @@ struct AppImageHubFeed {
 struct AppImageHubItem {
     name: Option<String>,
     description: Option<String>,
-    categories: Option<Vec<String>>,
+    categories: Option<Vec<Option<String>>>,
     authors: Option<Vec<AppImageHubAuthor>>,
-    links: Vec<AppImageHubLink>,
-    icons: Option<Vec<String>>,
+    links: Option<Vec<AppImageHubLink>>,
+    icons: Option<Vec<Option<String>>>,
 }
 
 #[derive(Debug, serde::Deserialize)]

src/ui/catalog_view.rs

@@ -175,15 +175,14 @@ pub fn build_catalog_page(db: &Rc<Database>) -> adw::NavigationPage {
                 let db_bg = Database::open().ok();
                 let result = gio::spawn_blocking(move || {
                     if let Some(ref db) = db_bg {
-                        catalog::sync_catalog(db, &catalog::CatalogSource {
-                            id: Some(1),
-                            name: "AppImageHub".to_string(),
-                            url: "https://appimage.github.io/feed.json".to_string(),
-                            source_type: catalog::CatalogType::AppImageHub,
-                            enabled: true,
-                            last_synced: None,
-                            app_count: 0,
-                        }).map_err(|e| e.to_string())
+                        catalog::ensure_default_sources(db);
+                        let sources = catalog::get_sources(db);
+                        if let Some(source) = sources.first() {
+                            catalog::sync_catalog(db, source)
+                                .map_err(|e| e.to_string())
+                        } else {
+                            Err("No catalog sources configured".to_string())
+                        }
                     } else {
                         Err("Failed to open database".to_string())
                     }