feat(vault): add get/create assets API in workflow

TODO: update vault.service.ts. Use MNEMONIC workflow to create real private_key_shard and content_inner_encrypted

src/services/assets.service.ts

@@ -142,11 +142,16 @@ export const assetsService = {
         body: JSON.stringify(asset),
       });
 
-      logApiDebug('Create Asset Response Status', response.status);
+      const responseStatus = response.status;
+      logApiDebug('Create Asset Response Status', responseStatus);
 
       if (!response.ok) {
         const errorData = await response.json().catch(() => ({}));
-        throw new Error(errorData.detail || 'Failed to create asset');
+        const detail = errorData.detail || 'Failed to create asset';
+        const message = responseStatus === 401 ? `Unauthorized (401): ${detail}` : detail;
+        const err = new Error(message) as Error & { status?: number };
+        err.status = responseStatus;
+        throw err;
       }
 
       return await response.json();