XDVD Sidecar Metadata
=====================

Option 1 writes a normal 2048-byte-sector raw ISO plus external metadata files.
The ISO remains logical sector data only; firmware-facing lead-in/control/auth
material is kept in the sidecar files.

Generated files:

  <title>[media].iso
  <title>[media].media.json   (media/layout profile, format xdvd-media-profile)
  <title>[media].xdvd.json    (legacy command-replay sidecar)
  <title>[media].ad_c0.bin
  <title>[media].pfi.bin
  <title>[media].dmi.bin

The emulator should use:

  .iso         -> READ(10) sector data
  .media.json  -> media identity, image/layout profile, observed media state
  .xdvd.json   -> compatibility command map / detailed SCSI response sidecar
  .ad_c0.bin   -> READ DVD STRUCTURE AD00FF02FDFFFE00066400C0 response
  .pfi.bin     -> READ DVD STRUCTURE format 0x00 response
  .dmi.bin     -> READ DVD STRUCTURE format 0x04 response / media ID

For retail Xbox DVD-9 option-1 images, the JSON/image section should identify:

  sector_count: 3431264
  byte_count:   7027228672
  visible_sector_count: 306112
  game_output_start_lba: 306112
  game_unlocked_source_start_lba: 32
  game_sector_count: 3125152
  layer_break_lba: 1913776
