add hetzner server module

modules/hetzner_server/variables.tf

@@ -0,0 +1,46 @@
+variable "name" {
+  type        = string
+  description = "Host name (used as prefix for the SSH key and firewall)"
+}
+
+variable "ssh_public_key" {
+  type        = string
+  description = "Public SSH key to manage the host"
+}
+
+variable "server_type" {
+  type        = string
+  description = "Hetzner server type (e.g. cx22)"
+}
+
+variable "image" {
+  type        = string
+  description = "OS image to boot (e.g. debian-13)"
+}
+
+variable "location" {
+  type        = string
+  description = "Hetzner location (fsn1, nbg1, hel1, ash1)"
+  default     = "nbg1"
+  validation {
+    condition     = contains(["fsn1", "nbg1", "hel1", "ash1"], var.location)
+    error_message = "location must be one of fsn1, nbg1, hel1, ash1."
+  }
+}
+
+variable "user_data" {
+  type        = string
+  description = "Pre-rendered cloud-init user data (optional). Caller renders it from a template."
+  default     = null
+}
+
+variable "firewall_rules" {
+  type = list(object({
+    direction  = string
+    protocol   = string
+    port       = string
+    source_ips = list(string)
+  }))
+  description = "Firewall rules applied to the host"
+  default = []
+}