vault: cut over to GCE Raft HA cluster, retire nook.family media stack

- dns-neuralplatform.tf: add vault.neuralplatform.ai A record → 34.54.164.21 (GCP LB)
  DNS-only (not proxied) so GCP managed TLS cert can provision correctly
- main.tf: remove vault.neuralplatform.ai from Cloudflare tunnel ingress
  (now served directly via GCP Global HTTPS LB)
- main.tf: remove watch.nook.family, jellyfin.nook.family, bazarr.nook.family
  from tunnel ingress (nook.family media stack retired; infra is Neuron-focused)

GCE Vault cluster already initialized and running (3-node Raft, active since
2026-05-04T16:05). Secrets migrated 48/48 from k3s vault. ESO ClusterSecretStore
validated against new vault. k3s vault-0 is now superseded.

servers/legion/dns-neuralplatform.tf

@@ -23,3 +23,16 @@ resource "cloudflare_record" "np_web_stage" {
   proxied = true
   ttl     = 1
 }
+
+# vault.neuralplatform.ai — GCE Raft HA Vault cluster via GCP Global HTTPS LB.
+# DNS-only (not proxied) — GCP managed TLS cert terminates at the LB.
+# Vault nodes listen on plain HTTP 8200 internally; LB does TLS.
+# IP: terraform output vault_lb_ip from servers/gcp workspace = 34.54.164.21
+resource "cloudflare_record" "np_vault" {
+  zone_id = local.zone_neuralplatform_ai
+  name    = "vault"
+  type    = "A"
+  content = "34.54.164.21"
+  proxied = false
+  ttl     = 60
+}