H-109 inherits the frozen exact dependency/physics chain from H-108/H-104/H-103/H-100/H-089.

New optimization-only code:
  h109_sub_megabyte_exact_wedge_io_audit.py

Frozen physics:
  p = 0
  H-089 WALL_CONTINUOUS
  sqrt(current-cell convergence) * sin(theta)^3
  K = 8.6816265415871847e-05
  current active FrostCell only
  no GR/Newton/planetary labels

H-109 computational change:
  * No learned surrogate.
  * No memory-mapped wedge during compact photon propagation.
  * Exact float64 wedge values are read by file offset through an unbuffered
    file handle.
  * Fixed compact direct-mapped cache: 4096 uint64 keys + 4096 float64 values
    = exactly 64 KiB numeric field payload.
  * Reference path is serialized and removed from RAM before compact transit.

Scientific limitation:
  H-109 tests exact photon-propagation field working RAM only. It does not claim
  source-to-wedge generation or exact disk storage are below 1 MiB.
