Fix prod scroll release metadata validation

[MarcStdt]

Summary

• update release workflow runtime image references to druid v0.1.249 / v0.1.249-steamcmd
• fix production port overrides, including pzserver main/main2/maintcp
• add release workflow validator for stale images and invalid production port flags
• wire validator into validate_all_scrolls.sh
• add explicit pzserver chunks so pzserver-prebuild does not publish serverfiles as one large layer
• raise cs2server-prebuild min disk to 70Gi based on live materialization size

Test plan

• make build-tree
• go test ./scripts/validate-release-workflow ./scripts/prebuild
• go run ./scripts/validate-release-workflow
• go run ./scripts/validate-scrolls.go
• ./scripts/validate_all_scrolls.sh

Prod E2E note

Direct CR wave 20260611t212000z in druid-prod showed current published pzserver metadata exposes only main=16261/udp, so direct validation cannot go fully green until this release metadata ships via CI/CD. Prebuild worker logs showed pzserver-prebuild stuck on one 950MB serverfiles layer and cs2server-prebuild materializing a ~60GB artifact; no prod patches were made.

[druid-infra]

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