[GUI] Live acquisition mode

[KedoKudo]

Summary

Add live acquisition mode for real-time visualization during detector operation.

Context

During beamline experiments or detector testing, users need to see data in real-time as it's being acquired.

Requirements

• Connect to live data source (network socket, shared memory, or file watching)
• Real-time histogram updates (configurable refresh rate)
• Live hit rate and statistics display
• Buffer management for continuous streaming
• Pause/resume without data loss
• Snapshot current state to file
• Integration with facility DAQ systems (stretch)

UI Concept

┌─ Live Mode ───────────────────────────────────────────────┐
│  Source: [Network ▼] Address: [localhost:8080]  [Connect] │
│                                                           │
│  Status: 🟢 Connected | Rate: 1.2M hits/sec | Buffer: 45% │
│                                                           │
│  [▶ Resume] [⏸ Pause] [📷 Snapshot] [⏹ Stop]              │
└───────────────────────────────────────────────────────────┘

Technical Notes

• Consider ZeroMQ or raw TCP for network streaming
• May require separate thread/async task for data ingestion
• Memory management critical for long acquisitions
• Could integrate with EPICS/NICOS for facility systems

References

• Deferred from [ENHANCEMENT] Improve GUI for neutron imaging and detector development #13
• Related to [GUI] Pipeline architecture: Full streaming (Raw → Neutrons) #25 (streaming pipeline)