Disable migrations by default - all migrations already applied

All existing migrations are from 2019-2020 and have been applied in
production for years. Running them on every deployment is wasteful.

Changes:
- Set migrations.enabled: false in values.yaml
- Added comments explaining when to enable migrations
- Only enable manually when adding NEW migrations with --set migrations.enabled=true

This reduces deployment time and database load for routine deployments.

Author: danieltruong

helm/eagle-api/values.yaml

@@ -120,8 +120,11 @@ autoscaling:
   targetCPUUtilizationPercentage: 80
 
 # Database migrations job
+# Note: All migrations are from 2019-2020 and have been applied in production.
+# Only enable this when adding NEW migrations to the codebase.
+# To run migrations: helm upgrade --set migrations.enabled=true
 migrations:
-  enabled: true
+  enabled: false
   image:
     repository: image-registry.openshift-image-registry.svc:5000/6cdc9e-tools/eagle-api
     tag: "latest"