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-consent/src/with-consent.test.ts

@@ -0,0 +1,55 @@
+import { describe, it, expect, expectTypeOf } from "vitest";
+import { withConsent, type ConsentChecked } from "@/with-consent";
+import type { IConsent } from "@/consent.interface";
+import { isConsentChecked } from "@repo/core-shared/conformance";
+
+function makeConsent(): IConsent {
+  return {
+    isGranted: () => true,
+    grant: () => Promise.resolve(),
+    withdraw: () => Promise.resolve(),
+    getCategories: () => [],
+  };
+}
+
+describe("withConsent", () => {
+  it("returns a ConsentChecked<F>", () => {
+    const consent = makeConsent();
+    const fn = async (_input: { id: string }) => ({ ok: true });
+    const wrapped = withConsent(consent, fn);
+    expectTypeOf(wrapped).toMatchTypeOf<ConsentChecked<typeof fn>>();
+  });
+
+  it("attaches __consentChecked as a non-enumerable property on the wrapped function", () => {
+    const consent = makeConsent();
+    const fn = async () => ({ ok: true });
+    const wrapped = withConsent(consent, fn);
+    expect(isConsentChecked(wrapped)).toBe(true);
+    expect(Object.keys(wrapped)).not.toContain("__consentChecked");
+  });
+
+  it("does NOT pollute the original input function with the brand", () => {
+    const consent = makeConsent();
+    const fn = async () => ({ ok: true });
+    const wrapped = withConsent(consent, fn);
+    expect(isConsentChecked(fn)).toBe(false);
+    expect(wrapped).not.toBe(fn);
+  });
+
+  it("passes input and output through unchanged", async () => {
+    const consent = makeConsent();
+    const fn = async (input: { id: string }) => ({ ok: true, id: input.id });
+    const wrapped = withConsent(consent, fn);
+    const result = await wrapped({ id: "abc" });
+    expect(result).toEqual({ ok: true, id: "abc" });
+  });
+
+  it("propagates errors", async () => {
+    const consent = makeConsent();
+    const err = new Error("boom");
+    const wrapped = withConsent(consent, async () => {
+      throw err;
+    });
+    await expect(wrapped()).rejects.toBe(err);
+  });
+});