Describe the bug

json.JSONDecodeError inherits from ValueError, but in run_agent.py the error classification treats ValueError as a local validation error (non-retryable). When a provider returns malformed JSON (transient parse failure), the agent fails immediately instead of retrying, causing unnecessary session failures on provider hiccups.

Steps to reproduce

1. Use a provider that occasionally returns malformed JSON responses
2. Observe that the agent fails immediately with no retry instead of retrying the request

Expected behavior

JSONDecodeError should be excluded from the local validation error classification and treated as a retryable transient error.

Environment

• Hermes Agent version: current main
• OS: any