feat(iac): establish Ansible baseline for Nginx, SearXNG, Valkey, and Certbot

- Reverse-engineer live Debian 13 (trixie) VPS state at miguelpedro.xyz.br
- Add modular Ansible roles: common, certbot, valkey, searxng, and nginx
- Encrypt SearXNG secret_key using ansible-vault in group_vars/all/vault.yml
- Cleanly remove unused example.com Nginx stub symlink (sites-enabled/miguelpedro.xyz.br)
- Scaffold cgit + fcgiwrap role (cgit_enabled: false) for upcoming deployment
- Add DISCOVERY_REPORT.md, COMMAND_LOG.md, README.md, and AGENT_INSTRUCTIONS.md with Self-Updating Protocol

1 files changed, 87 insertions, 0 deletions

diff --git a/roles/nginx/tasks/main.yml b/roles/nginx/tasks/main.yml
new file mode 100644
index 0000000..c4f55b6
--- /dev/null
+++ b/roles/nginx/tasks/main.yml
@@ -0,0 +1,87 @@
+---
+- name: Ensure nginx is installed
+  ansible.builtin.apt:
+    name:
+      - nginx
+    state: present
+
+- name: Ensure Nginx directories exist
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: directory
+    owner: root
+    group: root
+    mode: "0755"
+  loop:
+    - /etc/nginx/sites-available
+    - /etc/nginx/sites-enabled
+    - /etc/nginx/default.apps-available
+    - /etc/nginx/default.d
+    - "{{ default_web_root }}"
+
+- name: Deploy /etc/nginx/nginx.conf
+  ansible.builtin.template:
+    src: nginx.conf.j2
+    dest: /etc/nginx/nginx.conf
+    owner: root
+    group: root
+    mode: "0644"
+    validate: "/usr/sbin/nginx -t -c %s"
+  notify: Reload nginx
+
+- name: Deploy /etc/nginx/default.apps-available/searxng.conf
+  ansible.builtin.template:
+    src: default-app-searxng.conf.j2
+    dest: /etc/nginx/default.apps-available/searxng.conf
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Reload nginx
+
+- name: Enable /etc/nginx/default.d/searxng.conf symlink
+  ansible.builtin.file:
+    src: /etc/nginx/default.apps-available/searxng.conf
+    dest: /etc/nginx/default.d/searxng.conf
+    state: link
+  notify: Reload nginx
+
+- name: Deploy /etc/nginx/sites-available/default
+  ansible.builtin.template:
+    src: site-default.conf.j2
+    dest: /etc/nginx/sites-available/default
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Reload nginx
+
+- name: Deploy /etc/nginx/sites-available/searxng.conf
+  ansible.builtin.template:
+    src: site-searxng.conf.j2
+    dest: /etc/nginx/sites-available/searxng.conf
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Reload nginx
+
+- name: Enable active Nginx sites
+  ansible.builtin.file:
+    src: "/etc/nginx/sites-available/{{ item }}"
+    dest: "/etc/nginx/sites-enabled/{{ item }}"
+    state: link
+  loop:
+    - default
+    - searxng.conf
+  notify: Reload nginx
+
+- name: Remove unused/stub Nginx site symlinks (clean tracking)
+  ansible.builtin.file:
+    path: "/etc/nginx/sites-enabled/{{ item }}"
+    state: absent
+  loop: "{{ nginx_remove_unused_sites | default([]) }}"
+  notify: Reload nginx
+
+- name: Ensure nginx service is enabled and running
+  ansible.builtin.systemd:
+    name: nginx.service
+    enabled: true
+    state: started