refactor(ansible): move RouterOS config into a role

Move flat tasks/ and vars/routeros-secrets.yml into
roles/routeros/ with a main.yml that imports the domain
task files in order. Update playbooks/routeros.yml to
use the role instead of importing tasks directly.

ansible/roles/routeros/tasks/main.yml

@@ -0,0 +1,27 @@
+---
+- name: Preflight checks
+  ansible.builtin.import_tasks: preflight.yml
+
+- name: Base network configuration
+  ansible.builtin.import_tasks: base.yml
+
+- name: WAN and tunnel interfaces
+  ansible.builtin.import_tasks: wan.yml
+
+- name: Hardware and platform tuning
+  ansible.builtin.import_tasks: hardware.yml
+
+- name: RouterOS container configuration
+  ansible.builtin.import_tasks: containers.yml
+
+- name: Addressing configuration
+  ansible.builtin.import_tasks: addressing.yml
+
+- name: Firewall configuration
+  ansible.builtin.import_tasks: firewall.yml
+
+- name: Routing configuration
+  ansible.builtin.import_tasks: routing.yml
+
+- name: System configuration
+  ansible.builtin.import_tasks: system.yml