feat: pipeline on/off toggle with per-stage Helm control

- Added pipelineEnabled flag to Helm values (default: true)
- Worker services (scheduler, ingestion, parser, extractor, aggregation,
  recommendation, broker-adapter, lake-publisher) scale to 0 when disabled
- API services always run regardless of toggle
- Redis-based runtime toggle: POST /api/ops/pipeline/toggle
- Scheduler checks the flag before each cycle
- Frontend: green/red Pipeline ON/OFF button on the pipeline page
- Beta defaults to pipelineEnabled: false
- Base values.yaml: blanked external URLs (Ollama, Polygon, Alpaca)
  so stages only connect to what they explicitly configure

pipelines/harbor/values.yaml

@@ -65,6 +65,11 @@ trivy:
 metrics:
   enabled: false
 
+# Enable Redis cache layer for faster manifest lookups (avoids upstream checks)
+cache:
+  enabled: true
+  expireHours: 24
+
 # Resource limits — conservative for a 4-node cluster
 core:
   resources: