feat(P4): Nova rebrand — AWS resource migration (REQ-163)

Rename all acdl-* AWS resources → nova-* across terraform (DynamoDB,
Secrets Manager, Lambda, SNS, SG, KMS alias, ECS, ECR, IAM user/policy,
state bucket, ALB, VPC/subnet names). Lambda default table names → nova-*
(D-111). State bucket backend → nova-tfstate (-migrate-state documented).
New docs/NOVA_AWS_MIGRATION.md runbook (staged migration + rollback).
New scripts/migrate_dynamodb_data.py (scan+copy, dry-run default).
acdl-deploy- → nova-deploy- role ARN in deploy workflows. Test fixtures
updated; terraform validate + pytest + run_ci.sh PASS.

---ci---
project: acdl
phase: 4
milestone: v1.15
status: execute
---/ci---

modules/l1/vpc/terraform/locals.tf

@@ -1,7 +1,7 @@
 locals {
   cidr_block = var.cidr != null ? var.cidr : "10.0.0.0/16"
   az_list    = split(",", var.azs)
-  name_tag  = var.name != null ? var.name : "acdl-vpc"
+  name_tag   = var.name != null ? var.name : "nova-vpc"
 
   # Derive subnet CIDRs from the VPC CIDR
   subnet_cidrs = [