Fix 1 — symmetric OTLP trigger: ZbSerilogConfig.ApplyOpenTelemetryExport now activates only
when options.Exporter == ZbExporter.Otlp, matching the core OTel metrics/traces path. The
previous fallback that also triggered on a bare OtlpEndpoint is removed; OtlpEndpoint is the
address to use when Otlp is selected, not an independent enable.
Fix 2 — deterministic service.instance.id: ZbResource.InstanceId (MachineName:ProcessId) is
a new public property that produces a stable, process-unique id without a random GUID.
ZbResource.Configure passes autoGenerateServiceInstanceId:false + serviceInstanceId:InstanceId
so metrics and traces never get a random auto-generated id. ZbSerilogConfig.BuildResourceAttributes
adds service.instance.id from ZbResource.InstanceId so the Serilog OTLP log sink carries the
exact same value — all three signals now share an identical resource for cross-signal joins.
Tests: +2 in ZbResourceTests (InstanceId determinism, no-GUID check), +2 in RedactionTests
(service.instance.id parity assertion in BuildResourceAttributes, symmetric OTLP trigger tests).
Total: 9 + 14 = 23 tests, all green.
Joseph Doherty