Add sanoid Ansible role for ZFS snapshots and replication

Replaces manually deployed config files with a fully idempotent role:
installs sanoid, templates sanoid.conf and syncoid service/timer from
variables, enables both systemd timers. Removes static proxmox/sanoid.*
files. README rebuild section updated accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ansible/roles/sanoid/tasks/main.yml

@@ -0,0 +1,47 @@
+---
+- name: Install sanoid
+  ansible.builtin.apt:
+    name: sanoid
+    state: present
+    update_cache: true
+
+- name: Deploy sanoid.conf
+  ansible.builtin.template:
+    src: sanoid.conf.j2
+    dest: /etc/sanoid/sanoid.conf
+    owner: root
+    group: root
+    mode: '0644'
+  notify: Restart sanoid timer
+
+- name: Deploy syncoid systemd service
+  ansible.builtin.template:
+    src: syncoid.service.j2
+    dest: /etc/systemd/system/syncoid.service
+    owner: root
+    group: root
+    mode: '0644'
+  notify: Restart syncoid timer
+
+- name: Deploy syncoid systemd timer
+  ansible.builtin.template:
+    src: syncoid.timer.j2
+    dest: /etc/systemd/system/syncoid.timer
+    owner: root
+    group: root
+    mode: '0644'
+  notify: Restart syncoid timer
+
+- name: Enable and start sanoid timer
+  ansible.builtin.systemd:
+    name: sanoid.timer
+    enabled: true
+    state: started
+    daemon_reload: true
+
+- name: Enable and start syncoid timer
+  ansible.builtin.systemd:
+    name: syncoid.timer
+    enabled: true
+    state: started
+    daemon_reload: true