hosts: add testvm01, testvm02, testvm03 test hosts

Three permanent test hosts for validating deployment and bootstrapping
workflow. Each host configured with:
- Static IP (10.69.13.20-22/24)
- Vault AppRole integration
- Bootstrap from deploy-test-hosts branch

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

hosts/testvm02/default.nix

@@ -0,0 +1,5 @@
+{ ... }: {
+  imports = [
+    ./configuration.nix
+  ];
+}