feat(core-consent): scaffold package with types, IConsent, withConsent brand wrapper

- Add packages/core-consent with ConsentCategory, ConsentState,
  UserConsentState types and IConsent interface
- Add withConsent wrapper attaching __consentChecked brand at bind time;
  unit tests assert brand attachment and factory passthrough
- Add ConsentChecked<F> type to core-shared/conformance/brands.ts and
  isConsentChecked helper to brand-runtime.ts
- Extend FeatureManifest with requiresConsent?: readonly string[] field
- Extend assertFeatureConformance to require __consentChecked brand when
  requiresConsent.length > 0; synthetic fixture tests cover pass/fail cases
- Propagate __consentChecked in withSpan PROPAGATED_BRANDS so the outermost
  binding carries the brand

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/core-shared/src/instrumentation/with-span.ts

@@ -2,7 +2,12 @@ import type { ITracer, SpanOpts } from "./tracer.interface";
 import type { Instrumented } from "../conformance/brands";
 import { attachBrand } from "../conformance/brand-runtime";
 
-const PROPAGATED_BRANDS = ["__captured", "__audited", "__analyzed"] as const;
+const PROPAGATED_BRANDS = [
+  "__captured",
+  "__audited",
+  "__analyzed",
+  "__consentChecked",
+] as const;
 
 export function withSpan<Args extends unknown[], R, Extra extends object>(
   tracer: ITracer,