svc-bkp-rmt-2-loc: migrate pull script to Python + add unit tests; lock down backup-provider ACLs

- Replace Bash pull-specific-host.sh with Python pull-specific-host.py (argparse, identical logic)
- Update role vars and runner template to call python script
- Add __init__.py files for test discovery/imports
- Add unittest: tests/unit/roles/svc-bkp-rmt-2-loc/files/test_pull_specific_host.py (mocks subprocess/os/time; covers success, no types, find-fail, retry-exhaustion)
- Backup provider SSH wrapper: align allowed ls path (backup-docker-to-local)
- Split user role tasks: 01_core (sudoers), 02_permissions_ssh (SSH keys + wrapper), 03_permissions_folders (ownership + default ACLs + depth-limited chown/chmod)
- Ensure default ACLs grant rwx to 'backup' and none to group/other; keep sudo rsync working

Ref: ChatGPT discussion (2025-10-14) — https://chatgpt.com/share/68ee920a-9b98-800f-8806-ddcfe0255149

roles/sys-bkp-provider-user/tasks/01_core.yml

@@ -3,30 +3,6 @@
     name: backup
     create_home: yes
 
-- name: create .ssh directory
-  file:
-    path: /home/backup/.ssh
-    state: directory
-    owner: backup
-    group: backup
-    mode: '0700'
-
-- name: create /home/backup/.ssh/authorized_keys
-  template:
-    src: "authorized_keys.j2"
-    dest: /home/backup/.ssh/authorized_keys
-    owner: backup
-    group: backup
-    mode: '0644'
-
-- name: create /home/backup/ssh-wrapper.sh
-  copy:
-    src: "ssh-wrapper.sh"
-    dest: /home/backup/ssh-wrapper.sh
-    owner: backup
-    group: backup
-    mode: '0700'
-
 - name: grant backup sudo rights
   copy:
     src: "backup"
@@ -35,3 +11,9 @@
     owner: root
     group: root
   notify: sshd restart
+
+- include_tasks: 02_permissions_ssh.yml
+
+- include_tasks: 03_permissions_folders.yml
+
+- include_tasks: utils/run_once.yml