- Guard cancel_job() against TOCTOU: when dequeue() returns False the
pending job left the queue between snapshot and delete; return
CANCEL_UNKNOWN so callers never report cancelled=True for a remove
that did not happen.
- Validate each job_ids element in the batch cancel endpoint before
any queue access; unhashable or non-UUID values now return 400
instead of raising TypeError (500).
- Update batch HTTP tests to use canonical UUID ids (required now that
the endpoint validates id format) and add tests for the new guards.
Add two cancel endpoints under the jobs namespace so a job can be
cancelled by id without the caller needing to know whether the job is
running or pending, or branching between /interrupt and /queue.
- POST /api/jobs/{job_id}/cancel cancels one job by id. Idempotent: an
already-finished or unknown id returns 200 {"cancelled": false} rather
than an error.
- POST /api/jobs/cancel takes {"job_ids": [...]} and cancels a batch.
Fail-fast: if any id is unknown the request returns 404 listing the
unknown ids and cancels nothing (no partial side effects).
Both are state-agnostic and map onto the existing queue mechanics: a
running job is interrupted (same path as /interrupt), a pending job is
dequeued (same path as /queue {"delete": [...]}). The cancel logic lives
in comfy_execution.jobs as pure, unit-tested helpers; the server handlers
are thin wrappers. openapi.yaml documents both routes.