monitoring01: remove host and migrate services to monitoring02

Remove monitoring01 host configuration and unused service modules
(prometheus, grafana, loki, tempo, pyroscope). Migrate blackbox,
exportarr, and pve exporters to monitoring02 with scrape configs
moved to VictoriaMetrics. Update alert rules, terraform vault
policies/secrets, http-proxy entries, and documentation to reflect
the monitoring02 migration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

terraform/vault/secrets.tf

@@ -10,10 +10,6 @@ resource "vault_mount" "kv" {
 locals {
   secrets = {
     # Example host-specific secrets
-    # "hosts/monitoring01/grafana-admin" = {
-    #   auto_generate   = true
-    #   password_length = 32
-    # }
     # "hosts/ha1/mqtt-password" = {
     #   auto_generate   = true
     #   password_length = 24
@@ -35,11 +31,6 @@ locals {
     #   }
     # }
 
-    "hosts/monitoring01/grafana-admin" = {
-      auto_generate   = true
-      password_length = 32
-    }
-
     "hosts/ha1/mqtt-password" = {
       auto_generate   = true
       password_length = 24
@@ -57,8 +48,8 @@ locals {
       data          = { nkey = var.nats_nkey }
     }
 
-    # PVE exporter config for monitoring01
-    "hosts/monitoring01/pve-exporter" = {
+    # PVE exporter config for monitoring02
+    "hosts/monitoring02/pve-exporter" = {
       auto_generate = false
       data          = { config = var.pve_exporter_config }
     }
@@ -149,7 +140,7 @@ locals {
     }
 
     # Bearer token for scraping apiary metrics
-    "hosts/monitoring01/apiary-token" = {
+    "hosts/monitoring02/apiary-token" = {
       auto_generate   = true
       password_length = 64
     }