feat(delivery): add Ansible playbook for native MySQL provisioning

Add mysql-deploy.yml playbook for bare-metal MySQL 8.0 delivery via
AWX: parameter validation, resource preflight checks, apt install,
AppArmor adaptation, per-instance directory layout, Jinja2 config
template (buffer pool sizing, binlog, GTID), systemd template unit
(mysql-delivery@.service), admin account setup, and TCP health
verification. Includes example inventory.

Relates-to: #97

ansible/templates/mysql-instance.cnf.j2

@@ -0,0 +1,35 @@
+[mysqld]
+user=mysql
+basedir=/usr
+datadir={{ mysql_data_dir }}
+socket={{ mysql_run_dir }}/mysql.sock
+pid-file={{ mysql_run_dir }}/mysql.pid
+port={{ mysql_port_value }}
+bind-address=0.0.0.0
+mysqlx=0
+server-id={{ 101 + mysql_node_index | int }}
+log-error={{ mysql_log_dir }}/error.log
+slow-query-log=ON
+slow-query-log-file={{ mysql_log_dir }}/slow.log
+skip-name-resolve=ON
+max-connections=100
+innodb-buffer-pool-size={{ ((mysql_memory_mb_value | int) * 55 / 100) | int }}M
+innodb-log-file-size=128M
+log-bin={{ mysql_log_dir }}/mysql-bin
+binlog-format=ROW
+gtid-mode=ON
+enforce-gtid-consistency=ON
+relay-log={{ mysql_log_dir }}/relay-bin
+
+{% if topology == 'mgr_3' %}
+plugin-load-add=group_replication.so
+transaction-write-set-extraction=XXHASH64
+loose-group-replication-group-name={{ mgr_group_name }}
+loose-group-replication-start-on-boot=OFF
+loose-group-replication-local-address={{ ansible_host | default(inventory_hostname) }}:{{ mysql_port_value | int + 10000 }}
+loose-group-replication-group-seeds={% for host in ansible_play_hosts_all %}{{ hostvars[host].ansible_host | default(host) }}:{{ mysql_port_value | int + 10000 }}{% if not loop.last %},{% endif %}{% endfor %}
+loose-group-replication-ip-allowlist={% for host in ansible_play_hosts_all %}{{ hostvars[host].ansible_host | default(host) }}{% if not loop.last %},{% endif %}{% endfor %}
+loose-group-replication-single-primary-mode=ON
+loose-group-replication-enforce-update-everywhere-checks=OFF
+{% endif %}
+