docs(agents): clarify path-ref resolves to container-side HF cache path

Match the resolve_path_ref_on_node fix (dcb28fa): the substituted path is
the container-side path (host cache-dir prefix rewritten to
/root/.cache/huggingface), not the raw host path — the former is invalid
inside the container where args/env are consumed.

AGENTS.md

@@ -50,8 +50,10 @@ env = "XDG_CACHE_HOME"            # optional: injects -e <name>=<container path>
 # the path survives `huggingface-cli download` updates with no fragile
 # symlink. `container` is the placeholder name (e.g. `mtp_draft`) that the
 # recipe references as `{{mtp_draft}}` in args/env. The launcher substitutes
-# the resolved full HF cache path per-node (no bind-mount — the HF cache is
-# already mounted at /root/.cache/huggingface, so symlinks resolve correctly).
+# the resolved **container-side** HF cache path per-node — the host cache-dir
+# prefix (e.g. `/home/<user>/.cache/huggingface`) is rewritten to the
+# container mount target `/root/.cache/huggingface` (no bind-mount — the HF
+# cache is already mounted there, so symlinks resolve correctly).
 # Absent subfolder → serve aborts with a hint to `huggingface-cli download <repo>`.
 [[extra_mounts]]
 repo = "aidendle94/GLM-5.2-Hybrid-FP8-MXPF4"