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>

flake.nix

@@ -195,6 +195,33 @@
             ./hosts/vault01
           ];
         };
+        testvm01 = nixpkgs.lib.nixosSystem {
+          inherit system;
+          specialArgs = {
+            inherit inputs self sops-nix;
+          };
+          modules = commonModules ++ [
+            ./hosts/testvm01
+          ];
+        };
+        testvm02 = nixpkgs.lib.nixosSystem {
+          inherit system;
+          specialArgs = {
+            inherit inputs self sops-nix;
+          };
+          modules = commonModules ++ [
+            ./hosts/testvm02
+          ];
+        };
+        testvm03 = nixpkgs.lib.nixosSystem {
+          inherit system;
+          specialArgs = {
+            inherit inputs self sops-nix;
+          };
+          modules = commonModules ++ [
+            ./hosts/testvm03
+          ];
+        };
       };
       packages = forAllSystems (
         { pkgs }: