fix: disable pipeline workers and blank API keys in beta stage

Beta is for API testing only. Scale scheduler, ingestion, parser,
extractor, aggregation, recommendation, broker-adapter, and
lake-publisher to 0 replicas. Blank out Polygon and Alpaca keys.
Infra secrets (postgres, redis, minio) kept so API services work.

infra/helm/stonks-oracle/values-beta.yaml

@@ -54,8 +54,6 @@ config:
   MINIO_ENDPOINT: "minio.minio-service.svc.cluster.local:80"
   MINIO_SECURE: "false"
   BROKER_MODE: "paper"
-  # Block all external connections — beta is for API testing only
-  OLLAMA_BASE_URL: "http://localhost:99999"
   BROKER_PROVIDER: "none"
 
 ## Blank out all secrets so beta never talks to external APIs