Screen backends

• Remote CICS (MQ) — live CICS transactions over MQ (OLGATE). BMS + copybook map descriptors for layout.
• Remote IMS Connect — live IMS/DC screens over IMS Connect. MFS-only descriptors; MID/MOD pull loop in the Player.
• AS400 / 5250 (future) — remote transport later. DSPF map ingest will come through map-descriptor when that work lands.

The backend is chosen once on New application and cannot be changed.

Unlike [[product:ol-terminal|OL Terminal]], consumers do not use a browser 3270/5250 emulator.