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_l2_lifecycle_test.sh

@@ -17,8 +17,8 @@
 # positional args for parity with the L1 matrix, but $3 is accepted-but-
 # ignored here (documented, not a bug).
 #
-# Lifecycle mode (REQ-134): NOVA_LIFECYCLE_MODE (dual-read NOVA_* preferred,
-# ACDL_* fallback until P5) default "plan" runs
+# Lifecycle mode (REQ-134): NOVA_LIFECYCLE_MODE (NOVA_* only; ACDL_*
+# fallback removed in v1.15 P5) default "plan" runs
 # `run_platform.sh --plan-only` (fast, no AWS mutation). Set to "full" for
 # the real `--apply` against live AWS.
 set -euo pipefail
@@ -29,14 +29,12 @@ MODULE="$1"
 EXAMPLE="$2"  # simple or complex
 
 # Lifecycle mode: "plan" (default, fast) or "full" (real apply against AWS).
-# Dual-read: NOVA_* preferred, ACDL_* fallback (removed in P5).
+# NOVA_* env vars only (ACDL_* fallback removed in v1.15 P5, REQ-164).
 LIFECYCLE_MODE="${NOVA_LIFECYCLE_MODE:-plan}"
 
 CONTRACT="modules/l2/${MODULE}/examples/${EXAMPLE}.yml"
 
 # Point terraform_remote_state to the CI VPC state (not the platform VPC).
-# Set both NOVA_* (preferred by the dual-read helper) and ACDL_* (legacy
-# fallback) so any unmigrated reader finds the key until P5.
 export NOVA_REMOTE_STATE_KEY="spike/ci-vpc/terraform.tfstate"