Renames the matrix_mautrix_SERVICENAME_* placeholders in the common
mautrix bridges guide to matrix_bridge_mautrix_SERVICENAME_*, and fixes
prose in the matrix-bridge-steam role that referred to the old variable
prefix and to a misspelled (underscore-styled) systemd service name.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Part of adopting a uniform naming policy for bridge variables,
where the variable prefix matches the role directory name.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Replaces `community.docker.docker_image` with the modern
`docker_image_pull` and `docker_image_build` split modules. Drops the
`ansible_version` compatibility ladder and the now-redundant
`_container_image_force_pull` variable (the new pull module handles
registry refresh natively via `pull: always`). Also registers
`_container_image_build_result` so that a self-build rebuild correctly
triggers a service restart.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/5191.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Roles affected: appservice-discord, appservice-irc, beeper-linkedin,
heisenbridge, hookshot, mautrix-bluesky, mautrix-discord,
mautrix-gmessages, mautrix-googlechat, mautrix-signal, mautrix-slack,
mautrix-twitter, mautrix-whatsapp, mautrix-wsproxy, mx-puppet-groupme,
mx-puppet-steam, postmoogle, sms, steam, cactus-comments, element,
fluffychat, schildichat, conduit, corporal, dendrite,
ldap-registration-proxy, media-repo, pantalaimon,
prometheus-nginxlog-exporter, registration, sygnal, synapse-admin,
user-verification-service.

For each role: renamed _docker_image* variables to _container_image*
(and _docker_src_files_path to _container_src_files_path where
applicable), added deprecation entries in validate_config.yml, and
updated group_vars/docs references.

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

* Documentation update

* New files for role

* Update existing files to add support for matrix-steam-bridge

* Typos and misc fixes

* Change docker tag to latest until version # is stable

* Align bridge permissions

* Correct user localpart

* Remove trailing +

* Fix syslog identifier

* Actually enable the service correctly

* One more typo fix

* Third time's the charm

* Fix config file paths

* Fix config after bridge repo changes

* Add default appservice public address - set public_media to false by default for testing

* Fix default config for steamkit-service path

* Fix bluesky reference

* Fix default container path

* Fix appservice connection to http for internal, change port to standard 8080

* Fix appservice port

* Enable public_media by default, add labels

* Enable public_media by default, add labels

* Allow bridge to update its own config and generate public_media signing key

* Add deterministic public_media_signing_key, expose portal cleanup

* Change default public_media path to omit `matrix.` from the path as it has been found that URLs generated by the bridge will only match {{ matrix_domain }}

* Remove domain re-write

* Revert "Change default public_media path to omit `matrix.` from the path as it has been found that URLs generated by the bridge will only match {{ matrix_domain }}"

This reverts commit 5f399effb9.

* Fix TLS label if playbook TLS is disabled

* Match default bridge TLS config

* Related to 3daf14d69 and 60ab08014 which enable async media by default for mautrix-go bridges

* Adjust matrix-bridge-steam files to add new line at the end of files

* Pin matrix-bridge-steam (latest -> 1.0.3)

---------

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