AI Implementation feature(821): First-Start Create Admin Modal (#2)

frontend/src/app/features/setup/setup-create-admin.validators.ts

@@ -0,0 +1,20 @@
+export interface PasswordMatchGroupLike {
+  get(name: 'password' | 'passwordConfirm'): { value: string | null | undefined } | null;
+}
+
+export interface PasswordMatchResult {
+  passwordMismatch?: boolean;
+}
+
+/**
+ * Group-level validator for the "Confirm Password" field.
+ * Returns `{ passwordMismatch: true }` when the two values differ,
+ * or `null` when they match (or when either is empty, so that
+ * `required`/`minlength` validators can take over).
+ */
+export function passwordMatchValidator(group: PasswordMatchGroupLike): PasswordMatchResult | null {
+  const password = group.get('password')?.value;
+  const confirm = group.get('passwordConfirm')?.value;
+  if (!password || !confirm) return null;
+  return password === confirm ? null : { passwordMismatch: true };
+}