Fix OpenBao OIDC token exchange compatibility

src/internal/server/oidc/token_test.go

@@ -107,6 +107,7 @@ func seededSession(sessions *oidc.SessionStore, verifier string) (code string) {
 		PKCEChallenge:       challenge,
 		PKCEChallengeMethod: "S256",
 		State:               "state1",
+		Nonce:               "nonce1",
 		Username:            "alice",
 		Scopes:              []string{"openid", "profile", "email", "groups"},
 		ExpiresAt:           time.Now().Add(10 * time.Minute),
@@ -323,6 +324,9 @@ func TestTokenHandler_JWTClaims_CorrectSubAndIssuer(t *testing.T) {
 	if claims["aud"] != "test-client" {
 		t.Errorf("aud: expected test-client, got %v", claims["aud"])
 	}
+	if claims["nonce"] != "nonce1" {
+		t.Errorf("nonce: expected nonce1, got %v", claims["nonce"])
+	}
 }
 
 func TestTokenHandler_ScopeFiltering_ProfileScope(t *testing.T) {