workflow-fix: production-body test rule for seam-stubbed fns

Overview / Motivation

Auto-filed by /daily 2026-07-03 from a recursion-guard-parked workflow-fix candidate.

Goal

add an implementer-side rule: one production-body test per seam-stubbed function (boundary-only, signature-conformant fakes)

Workflow gap

• Bug observed: no implementer-side rule requires a production-body test per seam-stubbed function; boundary-only signature-conformant fakes can hide a broken production body (#906 family, producer-side half, out of #948's reviewer-check scope)
• Why it is a workflow gap: see candidate note
• Confidence (emitter): medium

Proposed change (candidate sketch — refine in planning)

add an implementer-side rule: one production-body test per seam-stubbed function (boundary-only, signature-conformant fakes)

Scope / surfaces

• Primary target: .claude/agents/experiment-implementer.md, .claude/agents/implementer.md, .claude/rules/code-style.md
• Grep the workflow surface for the pattern before editing; list every hit in the plan.

Constraints / invariants

• Workflow-surface only; scripts/workflow_lint.py --check-asks passes; ruff on touched files passes.

Provenance

• workflow_fix_target: .claude/agents/experiment-implementer.md, .claude/agents/implementer.md, .claude/rules/code-style.md
• fingerprint: 92f7aed09d28

source: prose-followup (methodology critic, Phase 2). Proposed: implementer-side rule — one production-body test per seam-stubbed function (boundary-only, signature-conformant fakes) — target_file: .claude/agents/experiment-implementer.md, .claude/agents/implementer.md, .claude/rules/code-style.md. The producer-side half of the #906 family; deliberately out of #948's reviewer-check scope. routed: parked — this session runs under workflow_fix_target recursion guard (.claude/rules/workflow-fix-on-bug.md § Recursion guard); log-and-notify only, next non-workflow-fix orchestrator pass may file it.