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---

schemas/modules-lifecycle-pipeline.schema.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://acdl.cloudinit.dev/schemas/modules-lifecycle-pipeline.schema.json",
-  "title": "ACDL Modules Lifecycle Pipeline Contract",
+  "$id": "https://nova.cloudinit.dev/schemas/modules-lifecycle-pipeline.schema.json",
+  "title": "Nova Modules Lifecycle Pipeline Contract",
   "description": "Declarative contract for the modules-lifecycle pipeline. Matrix-runs each L1 module's examples/{simple,complex}.yml contracts through apply→modify→destroy against live AWS. Both Gitea Actions (.gitea/workflows/modules-lifecycle.yml) and GitHub Actions (.github/workflows/modules-lifecycle.yml) implement this contract byte-identically.",
   "type": "object",
   "required": ["name", "triggers", "runner", "python_version", "terraform_version", "stages", "matrix"],