The getEnv() function in server.go always returned the default value,
preventing ACB_R2_ENDPOINT/ACB_B2_ENDPOINT from being read at runtime.
Also updated Dockerfile from golang:1.24 to golang:1.25 to match go.mod.
K8s manifests for acb-evolver and acb-api already exist in
declarative-config/k8s/iad-acb/ai-code-battle/ (added Apr 21).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>