verify(P3): dead-code-and-stale-prefix-cleanup — 4-layer verify PASS + ship

VERIFY: structural — dead export + stale comments + prefixes gone; behavioral — 616 tests + CI PASS; quality — env-override test updated.

---ci---
project: acdl
phase: 3
milestone: v1.16
status: complete
phase_role: execution
requirements:
  covered: [REQ-167]
  partial: []
---/ci---

scripts/run_platform.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# scripts/run_platform.sh - the ACDL platform pipeline.
+# scripts/run_platform.sh - the Nova platform pipeline.
 #
 # Usage:
 #   run_platform.sh <contract.yml>            (full e2e with AWS)
@@ -150,7 +150,6 @@ rm -rf "$WORK"; mkdir -p "$TF_DIR"
 echo "=== Step 0: environment onboarding check ==="
 if [ -n "$ENVIRONMENT_OVERRIDE" ]; then
   export NOVA_ENVIRONMENT_OVERRIDE="$ENVIRONMENT_OVERRIDE"
-  export ACDL_ENVIRONMENT_OVERRIDE="$ENVIRONMENT_OVERRIDE"  # legacy fallback, removed in P5
   python3 core/environment_check.py --env="$ENVIRONMENT_OVERRIDE" || {
     echo "FAIL: environment not bound — see the onboarding prompt above" >&2
     exit 1