feat: Add HA Kubernetes cluster with Terraform + Ansible

- 3x CX23 control plane nodes (HA)
- 4x CX33 worker nodes
- k3s with embedded etcd
- Hetzner CCM for load balancers
- Gitea CI/CD workflows
- Backblaze B2 for Terraform state

ansible/roles/k3s-agent/defaults/main.yml

@@ -0,0 +1,4 @@
+---
+k3s_version: latest
+k3s_server_url: ""
+k3s_token: ""

ansible/roles/k3s-agent/tasks/main.yml

@@ -0,0 +1,30 @@
+---
+- name: Check if k3s agent is already installed
+  stat:
+    path: /usr/local/bin/k3s-agent
+  register: k3s_agent_binary
+
+- name: Download k3s install script
+  get_url:
+    url: https://get.k3s.io
+    dest: /tmp/install-k3s.sh
+    mode: "0755"
+  when: not k3s_agent_binary.stat.exists
+
+- name: Install k3s agent
+  environment:
+    INSTALL_K3S_VERSION: "{{ k3s_version if k3s_version != 'latest' else '' }}"
+    K3S_URL: "{{ k3s_server_url }}"
+    K3S_TOKEN: "{{ k3s_token }}"
+  command: /tmp/install-k3s.sh agent
+  args:
+    creates: /usr/local/bin/k3s-agent
+  when: not k3s_agent_binary.stat.exists
+
+- name: Wait for k3s agent to be ready
+  command: systemctl is-active k3s-agent
+  register: agent_status
+  until: agent_status.stdout == "active"
+  retries: 30
+  delay: 10
+  changed_when: false