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

docker-compose.yml

@@ -51,6 +51,24 @@ services:
       retries: 10
       start_period: 20s
 
+  fs-events:
+    build:
+      context: .
+      dockerfile: apps/freeswitch-events/Dockerfile
+    container_name: b2bcall-fs-events
+    restart: unless-stopped
+    depends_on:
+      - freeswitch
+      - redis
+    environment:
+      ESL_HOST: freeswitch
+      ESL_PORT: "8021"
+      ESL_PASSWORD: ${ESL_PASSWORD}
+      # Hostnames internos do compose (freeswitch/redis), diferente do
+      # REDIS_URL do .env que aponta pra localhost (uso pelo apps/api, que
+      # ainda roda no host) — ver docs/NETWORK_ARCHITECTURE.md.
+      REDIS_URL: redis://:${REDIS_PASSWORD}@redis:6379
+
 secrets:
   freeswitch_pat:
     environment: FREESWITCH_PAT