feat: add diagnostics and telemetry runtime

tests/fixtures/diagnostics/forbidden/direct-console.ts

@@ -0,0 +1,3 @@
+export function leakToConsole(token: string) {
+  console.error("UNKNOWN_DIAGNOSTIC_EVENT", token);
+}

tests/fixtures/diagnostics/forbidden/raw-context.ts

@@ -0,0 +1,8 @@
+export function leakSensitiveContext(telemetry: {
+  emit(eventName: string, context: Record<string, unknown>): void;
+}) {
+  telemetry.emit("api.request.failed", {
+    authorization: "Bearer secret",
+    request_body: { email: "private@example.test" },
+  });
+}

tests/fixtures/typecheck/invalid-diagnostics-port.ts

@@ -0,0 +1,11 @@
+import type { DiagnosticsPort } from "../../../src/application/ports/diagnostics-port.js";
+import type { TelemetryPort } from "../../../src/application/ports/telemetry-port.js";
+
+declare const diagnostics: DiagnosticsPort;
+declare const telemetry: TelemetryPort;
+
+diagnostics.record({
+  level: "fatal",
+  eventId: "UNKNOWN_DIAGNOSTIC_EVENT",
+});
+telemetry.emit("unknown.telemetry.event", {});