fix(marketplace): use external icon URL when icon field is absolute

Many MCP / skill records store their icon as an absolute external URL
(simpleicons.org / iconify.design) rather than an uploaded file, so the
/resources/icon endpoint 404s and the card icon breaks. Add
resolveMarketplaceIconURL() which prefers an absolute http(s) icon field
and otherwise falls back to the resources endpoint.

web/src/app/home/add-extension/page.tsx

@@ -184,11 +184,12 @@ function AddExtensionContent() {
     const cloud = getCloudServiceClientSync();
     const a = installInfo.plugin_author || '';
     const n = installInfo.plugin_name || '';
-    if (installExtensionType === 'mcp')
-      return cloud.getMCPMarketplaceIconURL(a, n);
-    if (installExtensionType === 'skill')
-      return cloud.getSkillMarketplaceIconURL(a, n);
-    return cloud.getPluginIconURL(a, n);
+    return cloud.resolveMarketplaceIconURL(
+      installExtensionType,
+      a,
+      n,
+      installInfo.plugin_icon,
+    );
   })();
 
   const [popoverOpen, setPopoverOpen] = useState(false);
@@ -326,6 +327,7 @@ function AddExtensionContent() {
       plugin_version: plugin.latest_version,
       plugin_label: extractI18nObject(plugin.label) || plugin.name,
       plugin_description: extractI18nObject(plugin.description) || '',
+      plugin_icon: plugin.icon || '',
     });
     setInstallExtensionType(plugin.type || 'plugin');
     setPluginInstallStatus(PluginInstallStatus.ASK_CONFIRM);

web/src/app/home/plugins/components/plugin-market/PluginMarketComponent.tsx

@@ -216,12 +216,12 @@ function MarketPageContent({
   const transformToVO = useCallback(
     (plugin: PluginV4): PluginMarketCardVO => {
       const cloudClient = getCloudServiceClientSync();
-      const iconURL =
-        plugin.type === 'mcp'
-          ? cloudClient.getMCPMarketplaceIconURL(plugin.author, plugin.name)
-          : plugin.type === 'skill'
-            ? cloudClient.getSkillMarketplaceIconURL(plugin.author, plugin.name)
-            : cloudClient.getPluginIconURL(plugin.author, plugin.name);
+      const iconURL = cloudClient.resolveMarketplaceIconURL(
+        plugin.type,
+        plugin.author,
+        plugin.name,
+        plugin.icon,
+      );
 
       return new PluginMarketCardVO({
         pluginId: plugin.author + ' / ' + plugin.name,

web/src/app/home/plugins/components/plugin-market/RecommendationLists.tsx

@@ -23,13 +23,14 @@ function pluginToVO(
   t: (key: string) => string,
 ): PluginMarketCardVO {
   const cloudClient = getCloudServiceClientSync();
-  // Recommendation lists are mixed-type; resolve the icon per extension type.
-  const iconURL =
-    plugin.type === 'mcp'
-      ? cloudClient.getMCPMarketplaceIconURL(plugin.author, plugin.name)
-      : plugin.type === 'skill'
-        ? cloudClient.getSkillMarketplaceIconURL(plugin.author, plugin.name)
-        : cloudClient.getPluginIconURL(plugin.author, plugin.name);
+  // Recommendation lists are mixed-type; resolve the icon per extension type,
+  // preferring an absolute external icon URL when the record carries one.
+  const iconURL = cloudClient.resolveMarketplaceIconURL(
+    plugin.type,
+    plugin.author,
+    plugin.name,
+    plugin.icon,
+  );
 
   return new PluginMarketCardVO({
     pluginId: plugin.author + ' / ' + plugin.name,

web/src/app/infra/http/CloudServiceClient.ts

@@ -230,6 +230,29 @@ export class CloudServiceClient extends BaseHttpClient {
     return `${this.baseURL}/api/v1/marketplace/skills/${author}/${name}/resources/icon`;
   }
 
+  /**
+   * Resolve the best icon URL for a marketplace extension.
+   *
+   * Many MCP / skill records store their ``icon`` as an absolute external URL
+   * (e.g. simpleicons.org / iconify.design logos) rather than a file uploaded
+   * to Space storage. For those, the ``/resources/icon`` endpoint 404s, so we
+   * must use the external URL directly. Records whose ``icon`` is empty or a
+   * relative path fall back to the ``/resources/icon`` endpoint (real uploads).
+   */
+  public resolveMarketplaceIconURL(
+    type: 'plugin' | 'mcp' | 'skill' | undefined,
+    author: string,
+    name: string,
+    icon?: string,
+  ): string {
+    if (icon && /^https?:\/\//i.test(icon)) {
+      return icon;
+    }
+    if (type === 'mcp') return this.getMCPMarketplaceIconURL(author, name);
+    if (type === 'skill') return this.getSkillMarketplaceIconURL(author, name);
+    return this.getPluginIconURL(author, name);
+  }
+
   public getPluginAssetURL(
     author: string,
     pluginName: string,