Allow explicit context for OpenTelemetry logs

[riensen]

Summary

• allow OpenTelemetryLogsOutputPlugin callers to provide either a fixed OpenTelemetry Context or a per-record context resolver
• preserve the existing behavior when no context is configured, so the Logs SDK continues to capture context.active()
• add library-local SDK tests for active non-recording context, explicit context, resolver override, severity, body, and attributes

Root cause

OpenTelemetryLogsOutputPlugin.writeRecord() currently calls Logger.emit() without a context. The OpenTelemetry Logs SDK therefore snapshots context.active() at emit time. In framework integrations, that active context can contain a non-recording span whose span ID is never exported, even when the consumer already has the recording HTTP SERVER span context available. The resulting log record is correlated to a span that cannot be found in the trace backend.

This change keeps the plugin framework-agnostic: consumers can supply the correct context directly or resolve it lazily for each log record. There is no xotel-specific behavior.

Validation

• npm ci
• npm run build
• npx mocha src/test/unit-test/otel-output.test.js (3 passing)
• npm run lint
• git diff --check

The complete npm test run reaches 175 passing tests. Two existing dynamic-log-level acceptance tests fail because their checked-in JWT fixtures expired on 2026-07-02; the focused request-context test reproduces the same failures independently of this change.

[cla-assistant]

All committers have signed the CLA.