refactor: remove all legacy directus environment variables and standardize on postgres

src/payload/payload.config.ts

@@ -46,7 +46,7 @@ export default buildConfig({
       connectionString:
         process.env.DATABASE_URI ||
         process.env.POSTGRES_URI ||
-        `postgresql://${process.env.DIRECTUS_DB_USER || "directus"}:${process.env.DIRECTUS_DB_PASSWORD || "directus"}@127.0.0.1:5432/${process.env.DIRECTUS_DB_NAME || "directus"}`,
+        `postgresql://${process.env.POSTGRES_USER || "postgres"}:${process.env.POSTGRES_PASSWORD || "postgres"}@127.0.0.1:5432/${process.env.POSTGRES_DB || "payload"}`,
     },
     prodMigrations: migrations,
   }),