runpod: send the HuggingFace token to a pod, as environment and nothing else

pyannote is gated. On a pod it loaded from its baked venv, reached
from_pretrained, and stopped: 'the model is gated/unavailable'. The local
install has HF_TOKEN in its environment; a pod was never sent one — every gated
model was unservable remotely, not just this one.

It is resolved the way pyannote_worker already resolves it (request, env, token
file) and travels as pod ENVIRONMENT only. A test proves it reaches the pod and
appears nowhere else in the plan — not the seed list the pod parses, not the
catalogue, not the args.

Fixing this exposed a precedence bug: at provision time the plan's env was
applied OVER the model's own env, so a token a model was explicitly configured
with was silently replaced by whatever this process happened to have. The
model's own env wins now.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0182DhR1eFNPQyGmDrpHbedY