daily-fix: task.py WARN on v<k>-stamped note heads

Overview / Motivation

Auto-filed by /daily 2026-07-16 Step C from a parked prose candidate on task #1382 (Alternatives critic, plan round 1), sub-candidate (2).

Goal

Warn emitters at post time when a marker note head carries a 'v. ' version stamp, preventing the emission class the #1382 parser tolerance absorbs.

Workflow gap

• Bug observed: the poster-side _looks_field_led advisory WARN (scripts/task.py L137/L602) does not flag a 'v. '-stamped note head, so emitters keep echoing marker-version grammar into note heads; #1382 shipped only the read-side parser tolerance
• Why it is a workflow gap: Advisory WARNs at the mutation entrypoint are the project's mechanism for steering emitters; a WARN blind to a known bad shape leaves the class recurring.
• Confidence (emitter): low (emitter) — concrete file + change, filed per the 2026-06-11 standing directive
• verified-at-filing: grep -n '_looks_field_led' scripts/task.py -> 2 hits (def at L137, call at L602); no 'v'/version-stamp pattern in the predicate (absence claim; semantic probe: the predicate checks field-led note shapes only)

Proposed change (candidate diff sketch — refine in planning)

Extend _looks_field_led (or add a sibling advisory check at the same L602 call site) to match a leading r'v\d+.\s' note head and print the advisory WARN naming the stamp shape.

Scope / surfaces

• Primary target: scripts/task.py
• Grep the workflow surface for the pattern before editing and update every hit; list them in the plan.

Constraints / invariants

• Workflow-surface only — never experiment code, configs/, or tasks/.
• scripts/workflow_lint.py --check-asks passes; ruff on touched files passes.
• This session runs under a workflow_fix_target: Provenance line — it MUST NOT auto-route its own subagents' workflow-fix candidates (recursion guard).

Provenance

• fingerprint: f249739bb07c