Twelve actionable P1/P2 findings from round 28 reviewer aggregate.
Skipped #3 (studio.txt huggingface-hub bump) because the empirical
CI evidence in round 26 contradicts that suggestion: bumping the
pin there breaks installs that apply constraints.txt
(transformers==4.57.6 requires hub<1.0). The actual broken combo
only happens via the --no-deps no-torch path which is already
bumped in no-torch-runtime.txt and pyproject.toml huggingfacenotorch.
1. utils/datasets/llm_assist.py: split _HELPER_ADVISOR_REFCOUNT
into CACHE vs GPU counters. helper_advisor_owns_repo (used by
delete-cache) reads CACHE; helper_advisor_busy (used by public
handoffs) reads GPU. precache_helper_gguf now registers with
gpu_owner=False so a background pre-cache download does not
503 every chat / training / export / diffusion load.
2. utils/datasets/llm_assist.py: introduce _HELPER_ADVISOR_START_LOCK
and wrap the busy precheck + register pair in _run_with_helper
and _run_multi_pass_advisor. Two concurrent helper / advisor
invocations could both pass _gpu_workload_busy_for_helper before
either registered, then OOM each other.
3. utils/datasets/llm_assist.py: _gpu_workload_busy_for_helper now
also returns True when another helper/advisor already holds the
private LlamaCppBackend.
4. routes/inference.py: add _raise_if_helper_advisor_busy(workload)
that 503s when AI Assist owns the GPU. Wire it into both chat
load branches (GGUF + safetensors) BEFORE the existing
_release_export_for / _release_diffusion_for calls so we do not
first tear down an idle export / diffusion just to fail on the
helper check.
5. routes/training.py + routes/export.py + diffusion.load_model:
call the helper-busy check FIRST before any release helper
fires. Mirrors the chat-load ordering.
6. routes/inference.py _release_llama_for: poll
loading_model_identifier for up to 5 s after unload_model() so a
cancelled pending GGUF download has time to clear its
identifier. Mirrors the same wait round 26 added to the explicit
/api/inference/unload route.
7. core/inference/diffusion.py _release_chat_backend_for_diffusion:
same 5 s settling wait for cancelled pending GGUF downloads.
8. models/inference.py LoadRequest: validate every llama_extra_args
entry through _no_control_chars + _reject_embedded_hf_token.
The list was forwarded verbatim to a logged llama-server command
line, so a smuggled control char or hf_... token would land in
logs and subprocess args.
9. routes/models.py /gguf-download-progress: apply
_validate_logged_identifier to repo_id and variant, matching the
round 24 hardening on the adjacent generic /download-progress.
10. routes/inference.py diffusion-load RuntimeError classifier:
treat "AI Assist ..." messages as retryable 503 instead of 400
(round 28 P2 #15). Mirrors the round 18/19 markers for chat
unload failures.
Tests: 105 targeted + 1768 broader backend tests pass locally.
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