#797 store_audit_log fails with 'data is required' in EOD workflow

Error: Task 'store_audit_log' failed after 1 attempts: data is required Symptom: The `store_audit_log` task fails because template `{{combined_logs.audit_log}}` resolves to None. Analysis: - combine_all_logs task runs tools.code.exec and prints JSON: {audit_log: ..., entry_count: N} - Result should be stored with result_key as combined_logs - Variable resolver auto-extracts stdout and parses JSON - {{combined_logs.audit_log}} should resolve to the audit log string Investigation needed: 1. Check if result_key storage works correctly for tools.code.exec 2. Check if transaction rollback before state save caused data loss 3. Verify variable_resolver JSON extraction logic Note: Workflow completed all phases successfully (56 seconds) except the final S3 storage step. Acceptable for Issue #795 validation, but needs investigation for production.