clean up log.error

[ihrpr]

We have this pattern throughout the codebase:

except Exception as e:
    logger.error(f"Something failed: {e}")

Two issues:

1. Should use logger.exception() instead of logger.error() - it automatically includes the traceback
2. Most catches should be specific exceptions, not generic Exception

Changes

• Replaced logger.error() → logger.exception() in exception handlers
• Removed redundant {e} from messages (exception details are included automatically)
• Added guidelines to CLAUDE.md to prevent this pattern in future PRs

This pattern appears to be spreading because LLMs copy existing code context.