WriteProgramAsync resolved -path as a directory and combined it with
program.Name ("1" + "O0001" -> "1/O0001"), while ReadProgramAsync
resolved it as a program identifier under ProgramDirectory ("1" ->
"/PRG/1"). The write target therefore never matched the read target:
STOR went to a nonexistent relative dir and failed with "unable to
connect to remote server" (-204). Surfaced once ISS-018/019 stopped
masking it.
Per Mitsubishi NC Explorer manual IB-1500904, programs live under
PRG/USER and are addressed by their program name/number with no
extension. Resolve write the same way as read: ResolvePath is now
single-arg (path = identifier or full path, joined with
ProgramDirectory). program.Name is used for validation only.
Update write unit test to the symmetric contract and add a roundtrip
regression test (-path "1" -> /PRG/1).
Siemens/Fagor share the pattern but tie extension handling to name
(entangled with ISS-013); left open in ISS-020.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
