Route Laminar and agent-server INFO logs through structured non-error logging

Context

Several SDK/agent-server startup observability logs are INFO-level messages, but can be ingested as status:error because they are emitted through third-party/default stderr handlers instead of the SDK's structured stdout logging:

• "No path found in HTTP endpoint URL"
• "Laminar is already initialized"
• Uvicorn startup/shutdown messages such as "Uvicorn running on", "child process", "parent process", and "Received SIGTERM" when emitted by the agent server.

These should remain visible as INFO, not page application-failure monitors.

Investigation notes

Laminar

openhands-sdk/openhands/sdk/observability/laminar.py calls lmnr.Laminar.initialize(...) when observability env vars are present. In lmnr==0.7.49:

• No path found in HTTP endpoint URL... is emitted with logger.info(...) from lmnr/opentelemetry_lib/tracing/exporter.py.
• That logger is created with Laminar's get_default_logger(..., propagate=False), which attaches a plain logging.StreamHandler(); the default stream is stderr.
• Laminar is already initialized. Skipping initialization. is emitted with cls.__logger.info(...) from lmnr/sdk/laminar.py after Laminar._initialize_logger() attaches another default stderr StreamHandler.

So the Python log level is INFO, but the stream/formatter can make Datadog classify the record as status:error.

Agent-server/Uvicorn

In openhands-agent-server:

• openhands-agent-server/openhands/agent_server/logging_config.py defines the JSON access handler with stream: ext://sys.stderr.
• openhands-sdk/openhands/sdk/logger/logger.py uses logging.StreamHandler() without an explicit stream, which defaults to stderr for the root SDK handler.
• Uvicorn's startup/shutdown messages are INFO logs. If they are written to stderr, container log ingestion can classify them as error status.

Proposed fix

1. Normalize Laminar loggers after initialization:
   • remove Laminar-installed stderr handlers for lmnr* loggers, or replace them with SDK-compatible structured handlers;
   • set propagation so INFO records flow through the SDK logger once;
   • preserve INFO visibility rather than silencing the messages globally.
2. Update SDK/agent-server logging to route INFO/WARNING JSON logs to stdout and reserve stderr for real ERROR/CRITICAL records, or otherwise emit a Datadog-compatible status/severity field that overrides stream classification.
3. Adjust openhands-agent-server Uvicorn logging config so access/error INFO logs do not use stderr in production JSON mode.
4. Add tests that simulate Laminar/Uvicorn INFO records and assert they are emitted with INFO severity/status and not via stderr-only handlers.

Acceptance criteria

• No path found in HTTP endpoint URL and Laminar is already initialized are ingested as INFO, not status:error.
• Agent-server Uvicorn startup/shutdown INFO logs are ingested as INFO.
• Real ERROR/CRITICAL logs still surface as errors.

This issue was created by an AI agent (OpenHands) on behalf of the user.

Read openhands-sdk/openhands/sdk/observability/laminar.py and openhands-sdk/openhands/sdk/logger/logger.py, then inspect openhands-agent-server/openhands/agent_server/logging_config.py. Reproduce Laminar and Uvicorn INFO records and trace their handlers and streams. Add tests for INFO severity and stdout routing while confirming ERROR and CRITICAL logs remain errors.