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, 47 insertions, 0 deletions

diff --git a/roles/nginx/templates/site-searxng.conf.j2 b/roles/nginx/templates/site-searxng.conf.j2
new file mode 100644
index 0000000..67a5a2d
--- /dev/null
+++ b/roles/nginx/templates/site-searxng.conf.j2
@@ -0,0 +1,47 @@
+server {
+    server_name {{ searxng_domain }};
+
+    # Disable logging for user privacy
+    access_log /dev/null;
+    error_log  /dev/null;
+
+    # Security headers
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header Referrer-Policy "no-referrer" always;
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+
+    location / {
+        uwsgi_pass unix://{{ searxng_socket_path }};
+
+        include uwsgi_params;
+
+        uwsgi_param    HTTP_HOST             $host;
+        uwsgi_param    HTTP_CONNECTION       $http_connection;
+
+        # see flaskfix.py
+        uwsgi_param    HTTP_X_SCHEME         $scheme;
+
+        # see limiter.py
+        uwsgi_param    HTTP_X_REAL_IP        $remote_addr;
+        uwsgi_param    HTTP_X_FORWARDED_FOR  $proxy_add_x_forwarded_for;
+    }
+
+    listen 443 ssl; # managed by Certbot
+    listen [::]:443 ssl; # managed by Certbot
+    ssl_certificate /etc/letsencrypt/live/{{ searxng_domain }}/fullchain.pem; # managed by Certbot
+    ssl_certificate_key /etc/letsencrypt/live/{{ searxng_domain }}/privkey.pem; # managed by Certbot
+    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
+    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
+}
+
+server {
+    if ($host = {{ searxng_domain }}) {
+        return 301 https://$host$request_uri;
+    } # managed by Certbot
+
+    listen 80;
+    listen [::]:80;
+    server_name {{ searxng_domain }};
+    return 404; # managed by Certbot
+}