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---

docs/environments/index.md

@@ -60,7 +60,7 @@ invoke the **platform Lambda** — `acdl-contract-ingestor` — across
 accounts. The Lambda is invoked via a Function URL with IAM auth, so the
 grant is an inline IAM policy applied to the consumer's deploy role. The
 policy template lives at
-[`terraform/platform/consumer_invoke_policy.json`](https://github.com/acdl/acdl/blob/main/terraform/platform/consumer_invoke_policy.json)
+[`terraform/platform/consumer_invoke_policy.json`](https://github.com/nova/nova/blob/main/terraform/platform/consumer_invoke_policy.json)
 and is scoped via **ABAC**: the condition
 `aws:PrincipalTag/acdl:owner == ${consumerRepo}` ensures a repo can only
 invoke the Lambda when its principal tag matches its claimed identity.
@@ -83,16 +83,16 @@ is used for two purposes:
    prepared-status stub until then).
 
 The Lambda handler and the Terraform that deploys it live in
-[`core/lambda/contract_ingestor.py`](https://github.com/acdl/acdl/blob/main/core/lambda/contract_ingestor.py)
+[`core/lambda/contract_ingestor.py`](https://github.com/nova/nova/blob/main/core/lambda/contract_ingestor.py)
 and
-[`terraform/platform/main.tf`](https://github.com/acdl/acdl/blob/main/terraform/platform/main.tf)
+[`terraform/platform/main.tf`](https://github.com/nova/nova/blob/main/terraform/platform/main.tf)
 respectively.
 
 ## Onboarding scaffold (current state)
 
 The platform repo ships a minimal onboarding scaffold:
 
-- [`core/environments/`](https://github.com/acdl/acdl/blob/main/core/environments/)
+- [`core/environments/`](https://github.com/nova/nova/blob/main/core/environments/)
   — environment definitions (a sample `dev.json`).
 - `core/environment_check.py` — checks whether an environment is defined for
   a given contract's repo + environment name; prints the friendly onboarding