Eunchurn Park 30c50ef45b
perf(xtc): optimize XTCH grayscale rendering and memory usage
- Remove storeBwBuffer() requirement for grayscale rendering
  - Peak memory reduced from 144KB to 96KB
  - Use 4-pass rendering: BW display → LSB → MSB → grayscale → BW restore

- Optimize PageInfo struct (24→16 bytes)
  - Change offset from uint64_t to uint32_t (4GB file limit)
  - Saves ~15KB for large books (e.g., 1883 pages: 45KB → 30KB)

- Add storeBwBuffer() return value for error handling
- Add pixel distribution logging for debugging
- Fix LSB/MSB grayscale mapping per README spec
2025-12-28 18:04:48 +09:00
..
2025-12-21 18:42:06 +11:00