Comment-only pass over the Python this PR touches: drop what the code already
says, collapse multi-line explanations that still read on one line, and keep
the reasoning that is not recoverable from the code. No code, docstring
semantics or behaviour changes; verified with an AST comparison against the
previous revision, and the backend suite is unchanged (same 37 environment
failures as before: the API integration tests that need a live keyed server,
the flash-attn install hooks, and the GPU memory fields).
Route on-device single-checkpoint video folders through the single_file loader:
a bare local .safetensors directory (no model_index.json) is advertised as a
pipeline with no filename, so validation rejected it before it could load.
Reinterpret the pick as a single_file load of the sole checkpoint, mirroring the
image load route.
Treat a reserved-but-not-yet-spawned LLM training start as active in
is_training_active() so /images/load, /video/load, and /diffusion/start cannot
race the reserved run for VRAM during the pre-spawn free window. Mirrors the
diffusion training service reservation.
Resume an in-flight image generation on the Images page mount: probe
generate-progress, re-enter the poll loop, and refresh the gallery on completion
so a run started elsewhere is reflected and its saved image appears without a
manual refresh. Seed resident image defaults from the resolved base_repo rather
than a possibly path-shaped repo_id so the first resident generation uses the
right recipe.
Run backend.start_training off the event loop with asyncio.to_thread so the
synchronous diffusion/video unload calls (which wait on engine generation
locks) cannot freeze concurrent requests; guard against overlapping starts
with a _start_in_progress compare-and-set under the service lock.
Resolve bare diffusion dataset names directly under datasets_root() before
falling back to the generic resolver, so an unrelated LLM upload file or
recipe folder sharing the name cannot shadow the image dataset.
Reject exact duplicate filenames within one multipart upload batch: two
parts staged to the same destination would let the later tmp.replace
silently discard the earlier file. Case variants stay exempt per the
existing stem-guard contract.
Require an instance prompt in the train panel when only some images have
captions, since backend discovery silently skips uncaptioned images.
