fix some for iam

apps/api/src/common/env.ts

@@ -26,3 +26,21 @@ export function envOrNull(name: string): string | null {
   const trimmed = typeof raw === 'string' ? raw.trim() : '';
   return trimmed === '' ? null : trimmed;
 }
+
+/** Comma-separated env list. Blank entries are dropped. */
+export function envList(name: string): string[] {
+  const raw = envOrNull(name);
+  if (!raw) return [];
+  return raw.split(',').map((item) => item.trim()).filter(Boolean);
+}
+
+/**
+ * Exact string match. A requested URI that is not in the list is refused
+ * (null) instead of being replaced by another app's address.
+ * With no request, the first configured value is used.
+ */
+export function pickExactUri(requested: string | undefined, allowed: Array<string | null>): string | null {
+  const unique = [...new Set(allowed.filter((item): item is string => Boolean(item)))];
+  if (requested) return unique.includes(requested) ? requested : null;
+  return unique[0] ?? null;
+}