feat(core-consent): add PayloadConsent, RecordingConsent and DI binders

Implements the Payload-backed IConsent that reads/writes users.consentState
and emits CONSENT_GRANT/CONSENT_WITHDRAW audit entries via injected auditLog.
Adds RecordingConsent test double in core-testing for unit-test injection.
Adds bindProductionConsent/bindDevSeedConsent DI binders and InMemoryConsent
for dev/seed contexts. Contract tests cover grant/withdraw/isGranted round-trip,
audit entry shape, metadata persistence (bannerVersion/policyVersion/method),
and getCategories reflection of state.

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

packages/core-consent/src/consent.interface.ts

@@ -1,4 +1,8 @@
-import type { ConsentCategory, UserConsentState } from "./consent-types";
+import type {
+  ConsentCategory,
+  UserConsentState,
+  ConsentGrantMeta,
+} from "./consent-types";
 
 /**
  * Vendor-neutral consent management interface.
@@ -12,7 +16,7 @@ export interface IConsent {
   isGranted(category: ConsentCategory): boolean;
 
   /** Record a consent grant for the given category. */
-  grant(category: ConsentCategory): Promise<void>;
+  grant(category: ConsentCategory, meta?: ConsentGrantMeta): Promise<void>;
 
   /** Record a consent withdrawal for the given category. */
   withdraw(category: ConsentCategory): Promise<void>;