ServerDrawer: guard folder-related store lookups against undefined stores

plugins/server-drawer/src/components/FolderItem.tsx

@@ -30,7 +30,10 @@ function folderColor(color?: number | null): string {
 }
 
 function FolderBadge({ node }: { node: GuildNode }) {
-    const total = Flux?.useStateFromStores?.(
+    // Same guard as useFolderExpanded in utils/theme.ts - GuildReadStateStore is a one-shot lookup
+    // with no retry, and passing an undefined store into useStateFromStores throws instead of
+    // failing safely, which would take the whole drawer down, not just this badge.
+    const total = (Flux?.useStateFromStores && GuildReadStateStore) ? Flux.useStateFromStores(
         [GuildReadStateStore],
         () => {
             let sum = 0;
@@ -40,7 +43,7 @@ function FolderBadge({ node }: { node: GuildNode }) {
             return sum;
         },
         [node.children],
-    ) ?? 0;
+    ) : 0;
 
     if (total > 0) {
         return (

plugins/server-drawer/src/utils/theme.ts

@@ -13,7 +13,14 @@ export function useTheme() {
 }
 
 export function useFolderExpanded(folderId: string | number): boolean {
-    return Flux?.useStateFromStores?.(
+    // Confirmed live: an account with folders and one without exercise different code paths (this
+    // hook is only ever called by FolderItem, which only exists when there's a folder to render) -
+    // an account with no folders rendered fine while one with folders showed nothing at all.
+    // ExpandedGuildFolderStore is a one-shot findByStoreName at module-eval time with no retry, so
+    // if it hadn't registered yet, this passed [undefined] into useStateFromStores - which throws
+    // rather than returning safely, taking down the whole drawer render, not just this one folder.
+    if (!Flux?.useStateFromStores || !ExpandedGuildFolderStore) return false;
+    return Flux.useStateFromStores(
         [ExpandedGuildFolderStore],
         () => {
             const folders = ExpandedGuildFolderStore?.getExpandedFolders?.();