feat: add Event Socket integration (b2bcall-fs-events)

- packages/telephony: TelephonyProvider interface (agente.md secao 25) and
  FreeSwitchTelephonyProvider implementation over the 'esl' library
  (actively maintained, TypeScript-native, built-in reconnect-with-backoff
  satisfying secao 195); normalizeEslEvent() translates raw ESL events into
  the internal vocabulary (secao 24)
- apps/freeswitch-events (b2bcall-fs-events): permanent ESL connection,
  resubscribes on every reconnect, publishes normalized events to the
  'b2bcall:events' Redis pub/sub channel; containerized (Dockerfile +
  docker-compose service) since its whole job is reaching the freeswitch
  container by internal hostname
- packages/shared: reusable createLogger() (structured JSON per secao 189),
  fixed a BigInt serialization crash surfaced by the esl library's error
  stats
- found and fixed a real FreeSWITCH 1.11 default: without an explicit
  apply-inbound-acl, mod_event_socket silently rejects any non-loopback
  connection ('Access Denied, go away.') even with the correct password —
  added a dedicated ACL (loopback + the Docker Compose network range, never
  0.0.0.0/0) in infrastructure/freeswitch/overrides/autoload_configs/
- verified end-to-end with a local loopback test call: CALL_CREATED ->
  CALL_ANSWERED -> CALL_ENDED observed on the Redis channel with the
  correct callUuid and hangup cause
- docs/EVENT_SOCKET.md

infrastructure/freeswitch/Dockerfile

@@ -43,6 +43,8 @@ RUN --mount=type=secret,id=freeswitch_pat,required=true \
 # vanilla padrão por enquanto — serão substituídos por mod_xml_curl na fase
 # "Extensions/Trunks/Dialplan" (ver docs/FREESWITCH.md).
 COPY overrides/autoload_configs/modules.conf.xml /etc/freeswitch/autoload_configs/modules.conf.xml
+COPY overrides/autoload_configs/event_socket.conf.xml /etc/freeswitch/autoload_configs/event_socket.conf.xml
+COPY overrides/autoload_configs/acl.conf.xml /etc/freeswitch/autoload_configs/acl.conf.xml
 COPY entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh