fix(infra): use UUID for n8n credential id instead of hardcoded '1'

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ImTotem

infra/scripts/init_n8n.sh

@@ -64,7 +64,7 @@ setup_credential() {
 import json, sys
 sa = json.load(open('$GOOGLE_SERVICE_ACCOUNT_FILE'))
 cred = [{
-    'id': '1',
+    'id': str(__import__('uuid').uuid4()),
     'name': 'Google Sheets SA',
     'type': 'googleApi',
     'data': {