Initial commit: nult - Ansible deployment toolkit

Merged from veridion-gitea and veridion-act-runner-gitea repos.

nult (Null-T) - instant teleportation from Strugatsky's Noon Universe.
Like Null-T, this toolkit instantly deploys infrastructure.

Roles:
- gitea: Gitea server with PostgreSQL (Docker Compose)
- act_runner: Gitea Actions runner

Playbooks:
- gitea.yml: Deploy Gitea server
- act-runner.yml: Deploy Act Runner
- site.yml: Deploy all services

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

act-runner.yml

@@ -0,0 +1,53 @@
+---
+# =============================================================================
+# Gitea Act Runner Deployment Playbook
+# =============================================================================
+#
+# Deploys and configures Gitea Act Runner on Ubuntu servers.
+#
+# Usage:
+#   ansible-playbook -i inventory/hosts.yml act-runner.yml --ask-vault-pass
+#
+# Dry run:
+#   ansible-playbook -i inventory/hosts.yml act-runner.yml --check --diff --ask-vault-pass
+#
+# =============================================================================
+
+- name: Deploy Gitea Act Runner
+  hosts: runner_servers
+  become: true
+  gather_facts: true
+
+  pre_tasks:
+    - name: Validate target operating system
+      ansible.builtin.assert:
+        that:
+          - ansible_facts['distribution'] == "Ubuntu"
+          - ansible_facts['distribution_major_version'] | int >= 20
+        fail_msg: >-
+          This playbook requires Ubuntu 20.04 or later.
+          Detected: {{ ansible_facts['distribution'] }} {{ ansible_facts['distribution_version'] }}
+
+    - name: Update apt package cache
+      ansible.builtin.apt:
+        update_cache: true
+        cache_valid_time: 3600
+
+  roles:
+    - role: act_runner
+      tags: [act_runner]
+
+  post_tasks:
+    - name: Display deployment summary
+      ansible.builtin.debug:
+        msg:
+          - "=============================================="
+          - "Gitea Act Runner - Deployment Complete"
+          - "=============================================="
+          - "Runner name: {{ act_runner_name }}"
+          - "Gitea instance: {{ gitea_instance_url }}"
+          - "Service status: {{ 'RUNNING' if act_runner_service_status.status.ActiveState == 'active' else 'NOT RUNNING' }}"
+          - ""
+          - "Verify in Gitea UI:"
+          - "  {{ gitea_instance_url }}/-/admin/actions/runners"
+          - "=============================================="