feat: enforce DDS token access through common grants

.env.example

@@ -69,6 +69,7 @@ export DDSUSER_MY_PASSWORD="DdsGrant#My2026"
 export DDSUSER_PG_PASSWORD="DdsGrant#Pg2026"
 export DDSUSER_BOTH_PASSWORD="DdsGrant#Both26"
 export DDSUSER_NONE_PASSWORD="DdsGrant#None26"
+export DDSUSER_TOKEN_PASSWORD="DdsGrant#Token26"
 
 # --- (4) 원격 Postgres (AWS RDS, Cloud SQL, ...) ---
 # sql/source/postgres_setup.sql 가 여기로 customers 테이블/seed 생성.