fix(downloads): a suspended user's queued jobs wait, and a clip too big for the space left says so

A suspension now blocks the user's downloads as quota.resolve already advised: the worker leaves
their queued jobs unclaimed until it is lifted (the confirm says so). A cut clip larger than the
remaining storage is refused with its own message (not "storage is full"), and a clip's quota
refusal reads as a clip's in both languages. The cancel poll compares to JobStatus.RUNNING.

backend/tests/test_download_limits.py

@@ -155,6 +155,25 @@ def test_unlimited_user_is_never_excluded(db):
     assert _claim_job() == q.id
 
 
+def test_a_suspended_users_queued_jobs_wait(db):
+    # Suspending a user blocks their downloads (quota.resolve's advice): a job they queued before
+    # stays queued, unclaimed, and runs once the suspension is lifted.
+    s = User(email="suspended@example.com", is_suspended=True)
+    o = User(email="other@example.com")
+    db.add_all([s, o])
+    db.flush()
+    waits = _job(db, s.id, queue_pos=1)
+    served = _job(db, o.id, queue_pos=2)
+    db.commit()
+    assert _claim_job() == served.id
+    assert _claim_job() is None
+    db.expire_all()
+    assert db.get(DownloadJob, waits.id).status == "queued"
+    db.get(User, s.id).is_suspended = False
+    db.commit()
+    assert _claim_job() == waits.id
+
+
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