fix: opencode run does not emit OTLP traces even with experimental.openTelemetry enabled #13438

Summary

opencode run does not produce any trace spans in a local OTEL collector, even when experimental.openTelemetry is enabled and OTEL exporter env vars are set.

In the same environment, manual OTLP trace ingestion works, so collector/backend path is healthy.

Environment

• OpenCode version: 1.1.65
• OS: macOS (darwin)
• Local stack: OpenTelemetry Collector (otel/opentelemetry-collector-contrib:0.123.0) + Jaeger (jaegertracing/jaeger:2.4.0)

Reproduction

1. Enable OpenTelemetry feature in config:

   {
     "$schema": "https://opencode.ai/config.json",
     "experimental": {
       "openTelemetry": true
     }
   }

2. Start local collector + jaeger (OTLP HTTP on :4318, gRPC on :4317).
3. Send a manual OTLP trace to collector (POST /v1/traces) as control.
4. Run opencode with OTEL env:
   • OTEL_TRACES_EXPORTER=otlp
   • OTEL_METRICS_EXPORTER=none
   • OTEL_LOGS_EXPORTER=none
   • OTEL_EXPORTER_OTLP_ENDPOINT=http://127.0.0.1:4318
   • OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
   • OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=http/protobuf
   • OTEL_SERVICE_NAME=opencode-local-smoke
5. Compare collector trace count and logs before/after.

Observed Result

• Baseline trace count: 1
• After manual OTLP control trace: 2 (as expected)
• After opencode run: still 2 (no new trace)
• Collector debug logs only show manual services (manual-curl-test, manual-control), no opencode service.
• Jaeger /api/services also shows only manual test services.

Expected Result

With experimental.openTelemetry=true + OTEL exporter env vars, opencode run should emit spans to OTLP collector.

Additional Notes

Potentially related issues:

• Add OTEL export capabilities for observability and monitoring #12142 (OTEL export capabilities)
• experimental_telemetry metadata removed during LLM refactor #8193 (experimental_telemetry metadata regression)
• [FEATURE]: add OTEL integration #13171 (OTEL integration discussion)

This report is specifically about runtime emission behavior: collector path is verified healthy, but opencode spans are not emitted.