Add Matrix homeserver with MatrixRTC calling support

- Synapse + PostgreSQL + coturn + LiveKit + lk-jwt-service
- Caddy entries for mtx.alogins.net, lk.alogins.net, lkjwt.alogins.net
- well-known endpoints for Matrix client/server discovery and RTC transport
- Users: admin, elizaveta, aleksandra

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

matrix/livekit/livekit.yaml

@@ -0,0 +1,15 @@
+port: 7880
+rtc:
+  tcp_port: 7881
+  port_range_start: 50100
+  port_range_end: 50200
+  use_external_ip: true
+
+keys:
+  devkey: ef3ef4b903ca8469b09b2dd7ab6af529c4d2f3c95668f53832fc351cf67777a9
+
+room:
+  auto_create: false
+
+logging:
+  level: info