feat: add diagnostics and telemetry runtime

src/application/ports/telemetry-port.ts

@@ -0,0 +1,10 @@
+import type { TelemetryEventName } from "../../contracts/telemetry.js";
+
+export type { TelemetryEventName };
+
+export type TelemetryPort = Readonly<{
+  emit(
+    eventName: TelemetryEventName,
+    attributes: Record<string, unknown>,
+  ): void;
+}>;