fix(verifayda): format nested Fayda address objects into strings

apps/edr-freight-api/src/modules/verifayda/utils/client-assertion.util.ts

@@ -7,12 +7,15 @@ export interface GenerateClientAssertionInput {
   expiresIn?: string;
 }
 
+// Mirrors the National ID Program's own reference implementation
+// (fayda-auth-python): plain {alg: RS256} header, no kid, no jti — eSignet
+// resolves the verification key from client_id alone.
 export async function generateClientAssertion(
   input: GenerateClientAssertionInput,
 ): Promise<string> {
   const privateKey = await importJWK(input.privateJwk, 'RS256');
   return new SignJWT({})
-    .setProtectedHeader({ alg: 'RS256', typ: 'JWT' })
+    .setProtectedHeader({ alg: 'RS256' })
     .setIssuer(input.clientId)
     .setSubject(input.clientId)
     .setAudience(input.audience)