This:

- brings consistency - no more mixing `_name_prefix` and `_registry_prefix`
- adds extensibility - a future patch will allow reconfiguring all registry prefixes for all roles in the playbook

We still have `_docker_` vs `_container_` inconsistencies.
These may be worked on later.

* This push request is about handling Traefik ipallowlist to synapse-admin application.

It's my first push request. If I forgot something please let me know. :-)

* Changed position of variable and naming for better expandebility of traefik options

* Remove useless `noqa var-naming` comment and too many blank lines at the end of the file

---------

Co-authored-by: AkDk7 <joerg@pannbacker.email>
Co-authored-by: Slavi Pantaleev <slavi@devture.com>

https://github.com/etkecc/synapse-admin/releases/tag/v0.10.3-etke31

* synapse-admin v0.10.3-etke15: Upgrade to react-admin v5

* v0.10.3-etke16

* fix linter

* add _auto and _custom vars

* Use 2 spaces before #noqa var-naming

---------

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* fix synapse-admin image prefix

* fix typo

* switch to synapse-admin fork

* Fix typo

* Close unclosed ) and reword sentence

---------

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

As reported in https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3451#issuecomment-2331316593

Likely the solution to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3451

Related to 0241c71a4c

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3270#issuecomment-2143782962

With this change, it should be possible for people to adjust the Docker
dependency from `docker.service` to something else (e.g. `pkg-ContainerManager-dockerd.service`),
or to completely eliminate it by setting `devture_systemd_docker_base_docker_service_name` to an empty string.

This makes it easier for people to use the playbook against a Synology DSM server.

Related to:

- c203bef912
- https://github.com/Awesome-Technologies/synapse-admin/issues/468

0.9.x is broken: https://github.com/Awesome-Technologies/synapse-admin/issues/468

A fix for this major regression got merged 2 hours after 0.9.1 was tagged,
but one week later there's still no 0.9.2. Shame.

`always` is an nginx suffix, which shouldn't have been added to these.

This may proof useful to someone in the future.

We've had it on `matrix-nginx-proxy` before, but
our initial support for Traefik did not include any of these security
headers.