fix(api): use TRUSTED_ORIGINS for socket.io gateway CORS; add createTask API client

docker-compose.swarm.portainer.yml

@@ -128,8 +128,6 @@ services:
       # Matrix bridge (optional — configure after Synapse is running)
       MATRIX_HOMESERVER_URL: ${MATRIX_HOMESERVER_URL:-http://synapse:8008}
       MATRIX_ACCESS_TOKEN: ${MATRIX_ACCESS_TOKEN:-}
-      # System admin IDs (comma-separated user UUIDs) for auth settings access
-      SYSTEM_ADMIN_IDS: ${SYSTEM_ADMIN_IDS:-}
       MATRIX_BOT_USER_ID: ${MATRIX_BOT_USER_ID:-}
       MATRIX_CONTROL_ROOM_ID: ${MATRIX_CONTROL_ROOM_ID:-}
       MATRIX_WORKSPACE_ID: ${MATRIX_WORKSPACE_ID:-}