fix(error): show a toast error if file tree building fails

Author: Keshav-writes-code

apps/app/src/lib/file_tree/builder.ts

@@ -1,5 +1,6 @@
 import { type FileNode, type GenericPath } from '@/types';
 import { invoke } from '@tauri-apps/api/core';
+import { toast } from 'svelte-sonner';
 
 export async function build_file_tree_from_fs({
   path,
@@ -12,6 +13,13 @@ export async function build_file_tree_from_fs({
     });
   } catch (error) {
     console.error('Failed to build file tree:', error);
+    const description =
+      error instanceof Error
+        ? error.message
+        : typeof error === 'string'
+          ? error
+          : JSON.stringify(error);
+    toast.error('Failed to build file tree', { description });
     throw error;
   }
 }