feat(P3): Nova rebrand — SSM path + tag keys (REQ-161/162)

SSM path /acdl/{env}/{contractId}/{output} → /nova/... across
core/output_publisher + contract resolver + consumer docs. New
scripts/migrate_ssm_paths.py (copy/verify/delete, dry-run default).
AWS tag keys acdl:owner|environment|contract|cost-center|ref → nova:*
across terraform tagging + ABAC session policies (iam:ResourceTag/acdl:*
→ iam:ResourceTag/nova:*). nova_tagging.py hard mode (D-109 warn→hard).
tagging-standard.json tag-key values → nova:*. New
scripts/untag_acdl_keys.py (remove old acdl:* tags, dry-run default).
Test fixtures updated; pytest + run_ci.sh PASS.

---ci---
project: acdl
phase: 3
milestone: v1.15
status: execute
---/ci---

core/output_publisher.py

@@ -8,8 +8,10 @@ Two canonical mechanisms:
      strings, ALB DNS, S3 bucket URL, CloudFront domain). No raw secrets in
      the comment — only non-sensitive outputs (DNS names, ARNs, bucket names).
 
-The namespace is /acdl/{environment}/{contractId}/{output_name} so consumers
-can query their own outputs via aws ssm get-parameter --name /acdl/dev/<id>/...
+The namespace is /nova/{environment}/{contractId}/{output_name} so consumers
+can query their own outputs via aws ssm get-parameter --name /nova/dev/<id>/...
+(REQ-161, P3: migrated from /acdl/... ; scripts/migrate_ssm_paths.py copies
+existing /acdl/... parameters to /nova/... and deletes the old ones.)
 """
 
 import json
@@ -29,7 +31,7 @@ if _REPO_ROOT not in sys.path:
 
 from core import env as _envhelper
 
-SSM_PREFIX = "/acdl"
+SSM_PREFIX = "/nova"
 KMS_KEY_ID_ENV = "NOVA_KMS_KEY_ID"
 
 # Outputs that are safe to display in a PR comment (no secrets).
@@ -122,7 +124,7 @@ def format_comment(outputs, environment, contract_id, ssm_results=None):
     outputs are noted as 'published to SSM' without their values.
     """
     lines = [
-        f"### ACDL Deploy Outputs ({environment})",
+        f"### Nova Deploy Outputs ({environment})",
         "",
         f"**Contract:** `{contract_id}`",
         f"**Environment:** `{environment}`",
@@ -144,7 +146,7 @@ def format_comment(outputs, environment, contract_id, ssm_results=None):
             ssm_path = "—"
         lines.append(f"| `{name}` | {display} | {ssm_path} |")
     lines.append("")
-    lines.append("> Sensitive outputs are available via `aws ssm get-parameter --name /acdl/" + environment + "/" + contract_id + "/<output_name>` (KMS-encrypted SecureString).")
+    lines.append("> Sensitive outputs are available via `aws ssm get-parameter --name /nova/" + environment + "/" + contract_id + "/<output_name>` (KMS-encrypted SecureString).")
     return "\n".join(lines)