feat: AI VM stack (WP-12) and Alloy telemetry on k8s, legacy and DB VMs (WP-15)

WP-12(실험 설계서 6장) vm/ai-env: apply.sh(시크릿 4종을 Secret Manager에서 파일로, 미등록이면
성능 저하 모드로 기동), compose(agent 8080·hitl 8081·rag-db pgvector 0.8.7-pg16), ai.env(Discord
서버 Selfheal Lab 1557424985793101824, approvals 1557425140302872698, escalation 1557425282363691048,
OPENAI_MODEL gpt-6.1-sol 후보), 프롬프트 3종, 러너북 11종(조치별·토폴로지·3층 절차).

WP-15(실험 설계서 4.1·4.3): apps/alloy.yaml(Alloy Helm 1.13.0 DaemonSet, 클러스터링으로 KSM·Argo CD·
cadvisor 스크랩 분산, demo 등 파드 로그 → Loki), apps/kube-state-metrics.yaml(Helm 8.6.0).
legacy-api compose에 Alloy 사이드카(up{job="legacy-api"}, 컨테이너 로그). DB VM은
vm/postgres-common/alloy.sh로 apt 설치 + prometheus.exporter.postgres(pg_replication_lag_seconds)
+ custom query pg_is_wal_replay_paused + PostgreSQL 로그.

vm/harness/apply.sh: 준비 대기 루프의 curl에 || true(러너 재기동 순간 curl 56으로 중단되던 문제,
2026-10-08 harness-sync 실측).

vm/ai-env/runbooks/net-route-change.md

@@ -0,0 +1,5 @@
+# net.route_change (layer 2, large impact, reversible, Terraform path)
+
+When: the cross-cloud path (api pods -> VPN -> ILB -> legacy) is broken by a route or firewall problem that is not transient (BGP sessions down, routes missing on one side). Transient partitions and packet loss that already cleared need no action.
+
+Procedure: the harness records the proposal; the change itself is applied by an operator through Terraform (stacks/10-network). Undo: Terraform apply of the previous revision.