terraform+nix: Hetzner orchestrator server (cpx11, nixos-infect, cc-ci-orchestrator-hetzner flake host)

Adds terraform/ to provision a Hetzner cpx11 (2 vCPU / 2 GB dedicated AMD / 40 GB NVMe)
for the loops runtime, and a flake + NixOS host config to converge it — replacing the slow
b1 Incus VM. Mirrors the cc-ci server terraform (same nixos-infect pin, same pattern).

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

terraform/versions.tf

@@ -0,0 +1,14 @@
+terraform {
+  required_version = ">= 1.0"
+  required_providers {
+    hcloud = {
+      source  = "hetznercloud/hcloud"
+      version = "1.64.0"
+    }
+  }
+}
+
+# The hcloud provider reads HCLOUD_TOKEN from the environment automatically.
+# Never put the token value in any .tf file or .tfvars — keep it in the shell
+# environment (export HCLOUD_TOKEN=...) or pass via TF_VAR_hcloud_token.
+provider "hcloud" {}