Enable collectibles on mobile clients.

Fetch and cache the published catalog in the renderer when Electron is unavailable, then download selected CDN assets directly for Matrix upload.

src/app/features/settings/account/CollectiblesSection.tsx

@@ -14,8 +14,8 @@ import {
   DiscordCollectibleItem,
   collectibleKindLabel,
   defaultPreviewAspectRatio,
+  fetchPublishedCollectiblesCatalog,
   groupCollectibleItems,
-  isElectronCollectiblesAvailable,
   uploadCollectibleToMatrix,
   variantItemLabel,
 } from '../../../utils/discordCollectibles';
@@ -347,24 +347,26 @@ export function CollectiblesSection({ collectibles, onApply }: CollectiblesSecti
   const [error, setError] = useState<string>();
   const [selectedByGroup, setSelectedByGroup] = useState<Record<string, string>>({});
 
-  const desktopAvailable = isElectronCollectiblesAvailable();
-
   const loadCatalog = useCallback(async (force = false) => {
-    if (!desktopAvailable) return;
     setCatalogLoading(true);
     setCatalogError(undefined);
     try {
-      const result = await window.electron!.discordCollectibles!.fetchCatalog(force);
-      if (!result?.success || !result.data?.items) {
-        throw new Error(result?.error || 'Failed to load Discord catalog.');
+      const desktopCatalog = window.electron?.discordCollectibles;
+      if (desktopCatalog) {
+        const result = await desktopCatalog.fetchCatalog(force);
+        if (!result?.success || !result.data?.items) {
+          throw new Error(result?.error || 'Failed to load collectibles catalog.');
+        }
+        setItems(result.data.items as DiscordCollectibleItem[]);
+      } else {
+        setItems(await fetchPublishedCollectiblesCatalog(force));
       }
-      setItems(result.data.items as DiscordCollectibleItem[]);
     } catch (e) {
       setCatalogError(e instanceof Error ? e.message : 'Failed to load catalog.');
       setItems([]);
     }
     setCatalogLoading(false);
-  }, [desktopAvailable]);
+  }, []);
 
   useEffect(() => {
     loadCatalog();
@@ -431,17 +433,6 @@ export function CollectiblesSection({ collectibles, onApply }: CollectiblesSecti
     kind === 'avatar_decoration' && css.CollectibleGroupGridDecorations
   );
 
-  if (!desktopAvailable) {
-    return (
-      <Box direction="Column" gap="200">
-        <Text size="T200" style={{ opacity: 0.8 }}>
-          Discord profile overlays are available in the Paarrot desktop app. Assets are fetched live from
-          Discord and uploaded to your Matrix profile when you pick one.
-        </Text>
-      </Box>
-    );
-  }
-
   return (
     <Box direction="Column" gap="300">
       <Text size="T200" style={{ opacity: 0.8 }}>

src/app/utils/discordCollectibles.ts

@@ -37,9 +37,87 @@ export type DownloadedCollectibleAsset = DiscordCollectibleAsset & {
 };
 
 const CDN_HOST_RE = /(^|\.)(discordapp\.com|discordapp\.net|discord\.com)$/i;
+const PUBLISHED_CATALOG_URLS = [
+  'https://github.com/litruv/discord-collectibles/releases/download/latest/profileeffects.json',
+  'https://github.com/litruv/discord-collectibles/releases/download/latest/nameplate.json',
+  'https://github.com/litruv/discord-collectibles/releases/download/latest/avatardecorations.json',
+];
+const CATALOG_CACHE_KEY = 'paarrot.discordCollectiblesCatalog';
+const CATALOG_CACHE_TTL_MS = 6 * 60 * 60 * 1000;
 
-export function isElectronCollectiblesAvailable(): boolean {
-  return Boolean(window.electron?.discordCollectibles);
+type PublishedCatalog = {
+  schema_version: number;
+  fetchedAt: string;
+  items: DiscordCollectibleItem[];
+};
+
+function isPublishedCatalog(value: unknown): value is { schema_version: number; items: DiscordCollectibleItem[] } {
+  if (!value || typeof value !== 'object') return false;
+  const catalog = value as Record<string, unknown>;
+  return (
+    catalog.schema_version === 1 &&
+    Array.isArray(catalog.items) &&
+    catalog.items.every(
+      (item) =>
+        item &&
+        typeof item === 'object' &&
+        typeof (item as DiscordCollectibleItem).id === 'string' &&
+        Array.isArray((item as DiscordCollectibleItem).assets)
+    )
+  );
+}
+
+function loadCachedCatalog(): PublishedCatalog | undefined {
+  try {
+    const raw = localStorage.getItem(CATALOG_CACHE_KEY);
+    if (!raw) return undefined;
+    const cached = JSON.parse(raw) as PublishedCatalog;
+    if (
+      !isPublishedCatalog(cached) ||
+      typeof cached.fetchedAt !== 'string' ||
+      Date.now() - Date.parse(cached.fetchedAt) >= CATALOG_CACHE_TTL_MS
+    ) {
+      return undefined;
+    }
+    return cached;
+  } catch {
+    return undefined;
+  }
+}
+
+function saveCachedCatalog(catalog: PublishedCatalog): void {
+  try {
+    localStorage.setItem(CATALOG_CACHE_KEY, JSON.stringify(catalog));
+  } catch {
+    // A full or unavailable storage backend should not prevent catalog use.
+  }
+}
+
+export async function fetchPublishedCollectiblesCatalog(
+  force = false
+): Promise<DiscordCollectibleItem[]> {
+  const cached = loadCachedCatalog();
+  if (!force && cached) return cached.items;
+
+  try {
+    const documents = await Promise.all(
+      PUBLISHED_CATALOG_URLS.map(async (url) => {
+        const response = await fetch(url);
+        if (!response.ok) throw new Error(`Catalog request failed with HTTP ${response.status}.`);
+        const catalog = await response.json();
+        if (!isPublishedCatalog(catalog)) throw new Error('Catalog has an unsupported schema.');
+        return catalog;
+      })
+    );
+    const items = documents.flatMap((catalog) => catalog.items);
+    if (items.length === 0) throw new Error('Catalog is empty.');
+
+    saveCachedCatalog({ schema_version: 1, fetchedAt: new Date().toISOString(), items });
+    return items;
+  } catch (error) {
+    if (cached) return cached.items;
+    throw error;
+  }
 }
 
 function isCdnUrl(value: unknown): value is string {
@@ -73,22 +151,31 @@ export async function downloadCollectibleAssets(
   assets: DiscordCollectibleAsset[]
 ): Promise<DownloadedCollectibleAsset[]> {
   const api = window.electron?.discordCollectibles;
-  if (!api) {
-    throw new Error('Discord collectibles are only available in the Paarrot desktop app.');
+  if (api) {
+    const result = await api.downloadAssets(assets);
+    if (!result?.success || !result.data) {
+      throw new Error(result?.error || 'Failed to download collectible assets from Discord CDN.');
+    }
+    return result.data.map((asset) => ({
+      role: asset.role,
+      url: asset.url,
+      filename: asset.filename,
+      mimeType: asset.mimeType,
+      data: asset.data instanceof Uint8Array ? asset.data : new Uint8Array(asset.data),
+    }));
   }
 
-  const result = await api.downloadAssets(assets);
-  if (!result?.success || !result.data) {
-    throw new Error(result?.error || 'Failed to download collectible assets from Discord CDN.');
-  }
-
-  return result.data.map((asset) => ({
-    role: asset.role,
-    url: asset.url,
-    filename: asset.filename,
-    mimeType: asset.mimeType,
-    data: asset.data instanceof Uint8Array ? asset.data : new Uint8Array(asset.data),
-  }));
+  return Promise.all(
+    assets.map(async (asset) => {
+      if (!isCdnUrl(asset.url)) throw new Error('Collectible asset URL is not a Discord CDN URL.');
+      const response = await fetch(asset.url);
+      if (!response.ok) throw new Error(`Failed to download ${asset.filename}: HTTP ${response.status}.`);
+      return {
+        ...asset,
+        data: new Uint8Array(await response.arrayBuffer()),
+      };
+    })
+  );
 }
 
 export async function uploadCollectibleToMatrix(