Reference for how the scan pipeline actually works — process_scan()'s call order, the CurrentScan/Events/Sessions/DevicesView relationships, how a session actually "closes" (there is no close function), and the FIELD_SPECS field-write authority mechanism. Load this before modifying server/scan/session_events.py or server/scan/device_handling.py, or when reasoning about device presence, connect/disconnect events, or session/timeline behavior.