fix(telemetry): identical resource across all 3 signals (symmetric OTLP trigger + deterministic service.instance.id)

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.

ZB.MOM.WW.Telemetry/tests/ZB.MOM.WW.Telemetry.Tests/ZbResourceTests.cs

@@ -26,6 +26,8 @@ public sealed class ZbResourceTests
         Assert.Equal("site-7", attributes["site.id"]);
         Assert.Equal("central", attributes["node.role"]);
         Assert.Equal(Environment.MachineName, attributes["host.name"]);
+        // service.instance.id must be the deterministic MachineName:ProcessId — NOT a random GUID.
+        Assert.Equal(ZbResource.InstanceId, attributes["service.instance.id"]);
     }
 
     [Fact]
@@ -43,8 +45,29 @@ public sealed class ZbResourceTests
         Assert.Contains("service.name", keys);
         Assert.Contains("service.namespace", keys);
         Assert.Contains("host.name", keys);
+        // service.instance.id is always present (deterministic, not optional).
+        Assert.Contains("service.instance.id", keys);
         Assert.DoesNotContain("service.version", keys);
         Assert.DoesNotContain("site.id", keys);
         Assert.DoesNotContain("node.role", keys);
     }
+
+    [Fact]
+    public void InstanceId_is_deterministic_MachineName_colon_ProcessId()
+    {
+        // InstanceId must be stable within the process and follow the MachineName:ProcessId format.
+        var expected = $"{Environment.MachineName}:{Environment.ProcessId}";
+        Assert.Equal(expected, ZbResource.InstanceId);
+        // Calling it twice returns the same value (no random component).
+        Assert.Equal(ZbResource.InstanceId, ZbResource.InstanceId);
+    }
+
+    [Fact]
+    public void InstanceId_does_not_contain_a_random_guid()
+    {
+        // The old OTel SDK default was a random GUID; the deterministic id must NOT be a GUID.
+        Assert.False(
+            Guid.TryParse(ZbResource.InstanceId, out _),
+            $"service.instance.id must not be a GUID; got '{ZbResource.InstanceId}'");
+    }
 }