feat(P2): Nova rebrand — code/env-vars/consumer-path (REQ-158/159/160)

core/env.py dual-read helper (D-108); 21 ACDL_*→NOVA_* env vars migrated
across core/scripts/adapters/tests/workflows + .env/.env.secrets (key
rename, values stay). G-106 binding: run_platform.sh:288-289 +
regression_verify.py:309-312 dual-read (NOVA first, ACDL fallback).
G-108 binding: Gitea NOVA_* secrets created via API + workflow secrets:
refs updated (deploy.yml + modules-lifecycle.yml, .gitea + .github).
acdl_tagging.py→nova_tagging.py (D-109 warn mode, nova:* enforced).
.acdl/→.nova/ consumer path (resolver + deploy workflow + schema +
tests + docs). Test fixtures updated; pytest + run_ci.sh PASS.

---ci---
project: acdl
phase: 2
milestone: v1.15
status: execute
---/ci---

docs/presentations/assets/mmd/developer-experience-02-what-dev-does.mmd

@@ -2,7 +2,7 @@
 
 flowchart LR
     A["1. App code<br/>(top level of the repo)"] --> D["Push to main"]
-    B["2. Contract<br/>(.acdl/contract.yml)"] --> D
+    B["2. Contract<br/>(.nova/contract.yml)"] --> D
     C["3. CI definition<br/>(.github/workflows/deploy.yml<br/>— one 'uses:' line)"] --> D
     D --> E["Platform does the rest"]
 classDef accent fill:#1B1B1B,color:#fff,stroke:#D6002A,stroke-width:2px