Model inspection turned every coded host error into a selected-target
refusal, so EMFILE at open or EIO at header read on a valid model came
back as target_unavailable with advice to check the path. Callers were
told to reselect a model that was fine.
Only codes that describe the selected path (missing, not a directory,
symlink, name too long, non-regular, changed) keep that refusal, as the
Go provider already does. Other host errors reach the existing
execution_failure fallback with the path and reason.
Fixes#6004
Preserve unsupported GGUF version bytes and both UINT32 interpretations without inventing byte order at the shared parser. Keep existing layout support, typed errors, evidence identity, scoped reads and resource limits.
Validation: 78 focused tests, full static/architecture and documentation checks, real CLI/MCP version controls and an independently checked public model. Latest-head Codex found no issues; Greptile is 5/5 and all review threads are resolved.
Some CI remained pending at merge qualification. Merge under the human owner's explicit standing bypass authorization does not claim the full CI suite passed.
Fixes#5749.
amyanger