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/approle.tf

@@ -40,23 +40,13 @@ EOT
 # Define host access policies
 locals {
   host_policies = {
-    # Example: monitoring01 host
-    # "monitoring01" = {
-    #   paths = [
-    #     "secret/data/hosts/monitoring01/*",
-    #     "secret/data/services/prometheus/*",
-    #     "secret/data/services/grafana/*",
-    #     "secret/data/shared/smtp/*"
-    #   ]
-    #   extra_policies = ["some-other-policy"]  # Optional: additional policies
-    # }
-
-    # Example: ha1 host
+    # Example:
     # "ha1" = {
     #   paths = [
     #     "secret/data/hosts/ha1/*",
     #     "secret/data/shared/mqtt/*"
     #   ]
+    #   extra_policies = ["some-other-policy"]  # Optional: additional policies
     # }
 
     "ha1" = {
@@ -66,16 +56,6 @@ locals {
       ]
     }
 
-    "monitoring01" = {
-      paths = [
-        "secret/data/hosts/monitoring01/*",
-        "secret/data/shared/backup/*",
-        "secret/data/shared/nats/*",
-        "secret/data/services/exportarr/*",
-      ]
-      extra_policies = ["prometheus-metrics"]
-    }
-
     # Wave 1: hosts with no service secrets (only need vault.enable for future use)
     "nats1" = {
       paths = [