chore: remove old inventory for now and add vagrant

old inventory was never in use. Vagrant for local development

inventories/vagrant/host_vars/backend2/httbin.yml

@@ -0,0 +1,2 @@
+# Httpbin service configuration (overrides for this host)
+httpbin_domain: "httpbin-srv2.local.test"

inventories/vagrant/host_vars/backend2/main.yml

@@ -0,0 +1,3 @@
+---
+# Backend2 server configuration
+# This is a minimal test server for testing multi-backend routing

inventories/vagrant/host_vars/backend2/traefik.yml

@@ -0,0 +1,6 @@
+# Services to be exposed through the DMZ reverse proxy
+traefik_services:
+  - name: httpbin-srv2
+    domain: "{{ httpbin_domain }}"
+    port: 443
+    protocol: https