feat(P2): env-transition detect-and-destroy — REQ-282..287

- core/env_transition.py: detect_prior_env() + record_applied_env() via DynamoDB nova-contracts table (REQ-282,283)
- scripts/run_platform.sh Step 0b: detect env change, destroy prior env (deletion_protection=false, terraform init -reconfigure + destroy), emit ENV_DESTROYED evidence event, fail closed on destroy failure (REQ-284)
- scripts/run_platform.sh: record applied env after successful apply (REQ-285)
- .github/workflows/deploy.yml: pass NOVA_CONSUMER_REPO to run_platform.sh (REQ-286)
- adapters/terraform/adapter.py: doc comment on env-scoped state key (REQ-287)

No orphan path: if destroy fails, pipeline exits non-zero (no apply runs).

---ci---
project: acdl
phase: 2
milestone: v1.24
status: execute
requirements: [REQ-282,REQ-283,REQ-284,REQ-285,REQ-286,REQ-287]
---/ci---

.github/workflows/deploy.yml

@@ -110,6 +110,8 @@ jobs:
 
       - name: Run the platform pipeline
         working-directory: ${{ github.workspace }}
+        env:
+          NOVA_CONSUMER_REPO: ${{ github.repository }}
         run: |
           MODE_FLAG=""
           case "${{ inputs.mode }}" in