Two evict/OOM fixes on the diffusion load paths:
- The video load moved a pipeline onto the GPU (apply_memory_plan) and
committed it while holding no lock, so an unload / GPU-arbiter eviction --
which bumps the load token and then barriers on _generate_lock before
freeing -- could hand VIDEO to chat/images and let the new owner allocate
concurrently with the in-flight placement, OOMing. Hold _generate_lock
across placement + the locked commit, mirroring the image backend, so an
evicting owner waits until this worker's placement is torn down or
committed. Lock order stays _generate_lock -> _lock (unload takes _lock
then releases it before the barrier), so there is no deadlock.
- resolve_local_single_file reinterpreted an On-Device folder as a base
single_file load whenever it held exactly one .safetensors, so a PEFT LoRA
adapter folder (adapter_config.json + adapter_model.safetensors) with a
family-token name was picked as a base checkpoint, evicting the resident
model before from_single_file failed on the adapter weights. Skip adapter
folders (adapter_config.json) and the adapter_model basename so the pick
stays a pipeline load and 400s in validation, before the GPU handoff.
Adds regression tests for both.
cf0f5d5504