Update LiveKit Server role to v1.12.0-0

LiveKit v1.12.0 tightens TURN security: credentials now carry a TTL,
and TURN no longer relays to restricted peer CIDRs by default. The
role defaults match upstream's secure defaults and are appropriate
for typical playbook deployments.

Bumps the migration-validation gate accordingly so users are pointed
at the CHANGELOG entry on next run.

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

roles/custom/matrix_playbook_migration/defaults/main.yml

@@ -14,10 +14,13 @@ matrix_playbook_migration_validated_version: ''
 # The version that the playbook expects the user to have validated against.
 # This is bumped whenever a breaking change is introduced.
 # The value configured here needs to exist in `matrix_playbook_migration_breaking_changes` as well.
-matrix_playbook_migration_expected_version: "v2026.04.24.0"
+matrix_playbook_migration_expected_version: "v2026.05.18.0"
 
 # A list of breaking changes, used to inform users what changed between their validated version and the expected version.
 matrix_playbook_migration_breaking_changes:
+  - version: "v2026.05.18.0"
+    summary: "LiveKit Server has been upgraded to v1.12.0 — TURN no longer relays to restricted peer CIDRs (loopback, link-local, multicast, private, unspecified) by default; TURN credentials now carry a TTL (300s)"
+    changelog_url: "https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/CHANGELOG.md#2026-05-18"
   - version: "v2026.04.24.0"
     summary: "(BC Break) mautrix-telegram has been rewritten in Go (bridgev2) — the web-based login endpoint, old-style relaybot and several variables have been removed"
     changelog_url: "https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/CHANGELOG.md#2026-04-24"