feat(core-consent): add handlers and consentRouter tRPC router

Protocol-agnostic handlers (grant, withdraw, isGranted, getCategories)
in core-consent/handlers/ call IConsent methods and return typed results.

consentRouter uses a consent-specific tRPC context (userId + consentFactory)
so each procedure can resolve the per-user IConsent instance at call time.
Auth middleware guards all four procedures and maps UnauthenticatedError →
UNAUTHORIZED via defineErrorMiddleware from core-shared (no local duplicate).

76 tests passing; new handler and router code at 100% branch coverage.

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

pnpm-lock.yaml

@@ -592,6 +592,12 @@ importers:
       "@repo/core-shared":
         specifier: workspace:*
         version: link:../core-shared
+      "@trpc/server":
+        specifier: ^11.0.0
+        version: 11.16.0(typescript@5.9.3)
+      zod:
+        specifier: ^3.24.0
+        version: 3.25.76
     devDependencies:
       "@repo/core-eslint":
         specifier: workspace:*