feat(P1): Nova rebrand — docs/decks/prose/schema-$id/release-titles (REQ-155/156/157)

Rebrand ACDL/Agentic Cloud Delivery Platform → Nova across README, docs/,
decks (markdown + mermaid .mmd + HTML), pyproject.toml name/description,
schema $id URLs (acdl.cloudinit.dev→nova.cloudinit.dev), release.yml
title/workflow-name. Nova tagline added to README header + both deck title
slides + docs/vision.md (alongside existing North Star, D-106). S&P theme
untouched (D-107). New docs/NOVA_MIGRATION.md consumer guide. Data values
(env vars, resource names, tag keys, SSM/consumer paths) left for P2-P4.

---ci---
project: acdl
phase: 1
milestone: v1.15
status: execute
---/ci---

modules/l1/kms-key/README.md

@@ -42,7 +42,7 @@ rotation enabled. One key per L2 deployment (no shared keys).
   "type": "aws:kms:key",
   "module": "kms-key@1.0.0",
   "inputs": {
-    "description": "ACDL per-stack CMK",
+    "description": "Nova per-stack CMK",
     "region": "us-east-1"
   }
 }