v0.96 — IRW header format standardized

v0.96

• IRW header format standardized — All IRW output now uses the reference 0x44-byte header format:
  • Magic 0x00640194 at offset 0x20
  • ROM address at 0x2C
  • Data-only size at 0x30 (header-exclusive)
  • uint16 LE checksum at 0x34 (trailing odd byte discarded)
  • Constant 0x00000004 at 0x38
  • Version string unified to 03/14/95 for all modes
  • See irw-header.md for the full specification
• Always-on header summary output (Size, Magic, Addr, Dsize, Cksum, etc.)
• Fixes BIGSREC.EXE compatibility for all IRW files