fix(admin-v2): Add missing utils and DSFA components for build

- Add cn() utility function for className merging
- Add DSFACard, RiskMatrix, ApprovalPanel components

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

admin-v2/lib/utils.ts

@@ -0,0 +1,7 @@
+/**
+ * Utility function for merging class names.
+ * Filters out falsy values and joins with spaces.
+ */
+export function cn(...classes: (string | undefined | null | false)[]): string {
+  return classes.filter(Boolean).join(' ')
+}