feat(core-audit): withAudit wraps and attaches runtime __audited marker

packages/core-audit/src/with-audit.ts

@@ -1,25 +1,24 @@
 import type { IAuditLog } from "./audit-log.interface";
+import { attachBrand } from "@repo/core-shared/conformance";
 
 /**
  * Phantom-type brand attached at wrap time by `withAudit`. The conformance
  * system uses this as the type-level seam for mutating use cases that
  * declare `audits: [...]` in their manifest — without `__audited`, the
  * binding is not assignable to `ProductionUseCase<I, O, M>` when M demands
- * it.
+ * it. At runtime the brand is a non-enumerable property attached by
+ * `attachBrand` from `@repo/core-shared/conformance`, so the boot-time
+ * assertion can verify the binding went through the audit-aware path.
  */
 export type Audited<F> = F & { readonly __audited: true };
 
 /**
- * Use-case wrapper applied at DI bind time. In milestone i this is a
- * brand-only attachment: it does not yet automatically call `auditLog.record`.
- * Use cases continue to call `auditLog.record(...)` in their own bodies; the
- * wrapper exists to make "binding was bound through the audit-aware path"
- * type-checkable at compile time.
- *
- * A future story may move auditing logic out of factory bodies and into the
- * wrapper itself (driven by manifest declarations) — but that requires the
- * manifest's `audits[]` entries to fully specify what gets recorded, which
- * is out of scope here.
+ * Use-case wrapper applied at DI bind time. The wrapper is a thin closure
+ * that forwards to `fn` unchanged and carries the `__audited` brand. The
+ * forward closure (instead of returning `fn` directly) keeps the brand on
+ * a fresh function so the caller's original `fn` is not mutated — important
+ * when the same factory output is used elsewhere unwrapped (dev-seed paths,
+ * tests).
  */
 export function withAudit<Args extends unknown[], R>(
   // TODO(conformance milestone iii+): wire automated recording from manifest
@@ -31,5 +30,7 @@ export function withAudit<Args extends unknown[], R>(
   fn: (...args: Args) => Promise<R>,
 ): Audited<(...args: Args) => Promise<R>> {
   void auditLog;
-  return fn as Audited<(...args: Args) => Promise<R>>;
+  const wrapped: (...args: Args) => Promise<R> = (...args) => fn(...args);
+  attachBrand(wrapped, "__audited");
+  return wrapped as Audited<(...args: Args) => Promise<R>>;
 }