Reformat `{{ { ... }[engine] }}` dict-in-Jinja-expressions across
bot/bridge role defaults for consistent indentation (tabs -> spaces).
Also: fix a missing space in a Jinja `+` expression in matrix-static-files,
and fix indentation in the caddy2-in-container example.

The original PR also renamed `galaxy/<role>` role references to just
`<role>` in setup.yml and jitsi_jvb.yml; those were dropped here because
Ansible does not recurse into subdirectories of `roles/` by default and
no `roles_path` is configured in ansible.cfg, so the rename would break
role resolution.

Co-Authored-By: Slavi Pantaleev <slavi@devture.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>

For each of the 34 roles (3 clients, 9 bots, 22 bridges), this commit:
- Adds `_restart_necessary: false` default variable
- Adds `register:` directives to config/image/systemd tasks
- Computes `_restart_necessary` via set_fact (OR of all .changed results)
- Wires `(_restart_necessary | bool)` in group_vars/matrix_servers

This allows the systemd service manager to skip unnecessary restarts
when running install-* tags and nothing actually changed.

Service roles and complex multi-service roles will follow separately.

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

Refer fd39392ec5 as well

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

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.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Rename variables matrix_bot_postmoogle_* with matrix_postmoogle_*

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Rename file names and references to those files

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Move variables block for /matrix-bridge-postmoogle

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Rename matrix_playbook_bot_postmoogle_ to matrix_playbook_bridge_postmoogle_

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Add matrix_playbook_migration_matrix_postmoogle_migration_validation_enabled

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

* Replace an install tag example with "-bot" prefix

The previous example seems to have been selected to show how components whose name contains "-bot-" needed to be specified.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

---------

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>
Co-authored-by: Suguru Hirahara <acioustick@noreply.codeberg.org>