Models in EXO_MODELS_PATH are pre-downloaded into read-only directories
and must not be deleted. The DownloadCoordinator had no awareness of
these paths, so they never appeared as completed downloads in cluster
state, and the bench harness could attempt to delete them when freeing
disk space.
Added a `read_only: bool` field to `DownloadCompleted` (default False).
The DownloadCoordinator now checks `resolve_model_in_path` in
`_start_download`, proactively scans EXO_MODELS_PATH in
`_emit_existing_download_progress` to emit DownloadCompleted events for
all pre-downloaded models (overriding DownloadPending from the regular
scan), and refuses deletion of read-only models. The bench harness
filters out read-only models from deletion candidates.
Test plan:
- Ran with EXO_MODELS_PATH. Available models now show as downloaded in
the UI. There isn't good UI for the fact they can't be deleted, but it
should work with exo_bench.
Jake Hillion
ab9273e723