argo-lob-sweep.sh's awk substitution for # __SWEEP_CELLS__ matched BOTH
the actual marker (line 110, whitespace-indented) AND the docstring
reference at the top of the template that mentions `# __SWEEP_CELLS__`
inside a sentence (line 8). Result: cell task was injected twice,
once before `apiVersion:` (breaking kubectl apply with 'invalid object'
validation error) and once at the correct DAG location.
Fix: anchor the match to lines that START with whitespace + the marker
(^[[:space:]]+# __SWEEP_CELLS__), so the docstring sentence (which has
'# The' first) no longer matches.
sweep_smoke.yaml: rewrite from the spec's idealised (axes:/windows:)
schema to the actual base:/cells: schema that fxt-backtest sweep +
argo-lob-sweep.sh parse. Hardcodes SHA 58b5ebbd3 (the production
training run); bounds smoke runtime via max_events=100000.
Verified: smoke sweep workflow lob-backtest-sweep-hxwmq submits cleanly
and starts running.