fix(infra): resolve CORS error and Nginx 502 Bad Gateway

- Update Hydra and Kratos CORS config to specify allowed origins explicitly instead of using wildcard with allow_credentials: true
- Fix Nginx upstream resolution for Oathkeeper to use correct container hostname (ory_oathkeeper)

docker/ory/oathkeeper/rules.active.json

@@ -156,4 +156,4 @@
     "authorizer": { "handler": "allow" },
     "mutators": [{ "handler": "noop" }]
   }
-]
+]