workflow-fix: add eval_results/issue_1481 to tests/sparse_cones.txt (issue-1947 tests collect in sparse worktrees)

Overview / Motivation

Auto-filed by the workflow-fix-on-bug protocol from a prose follow-up raised on task #2021 (emitting agent: implementer, unit A).

Goal

Add eval_results/issue_1481 to tests/sparse_cones.txt so tests/test_issue1947_resume_matrix.py (and the other issue-1947 tests importing scripts/issue1947_cells.py) collect/run in fresh sparse worktrees without a manual git sparse-checkout add.

Workflow gap

• Bug observed: tests/test_issue1947_resume_matrix.py fails at collection in any sparse worktree lacking the eval_results/issue_1481 cone; the #2021 unit-A implementer had to run git -C "$WT" sparse-checkout add eval_results/issue_1481 by hand (16/16 passed after).
• Why it is a workflow gap: CLAUDE.md § sparse-worktree test gate mandates that any test hard-reading repo_root()/eval_results/issue_<M>/... gets its dir added to the tests/sparse_cones.txt registry consumed by scripts/new_worktree.sh; a missing line makes every fresh sparse worktree's Step 9c gate red on an untouched test (the #671 class).
• Confidence (emitter): high
• verified-at-filing: grep -n 'issue_1481' tests/sparse_cones.txt → 0 hits (absence claim — the registry line is missing; 2026-08-02). Call-hop trace (clause g): symptom site = tests/test_issue1947_resume_matrix.py (imports issue1947_datagen → issue1947_cells); construction site = scripts/issue1947_cells.py:43 (VERDICT_MANIFEST_PATH = REPO_ROOT / "eval_results/issue_1481/analysis/verdict_manifest.json", read at L113 with a raise naming the manual sparse-checkout remedy at L111). Landed-fix history: git log --oneline --since='7 days ago' -- tests/sparse_cones.txt → 1 commit (ded60e3fa8, task #1776 — adds a DIFFERENT cone, the issue1776 phase3 manifest; not this fix).

Proposed change (candidate diff sketch — refine in planning)

+ eval_results/issue_1481

(one registry line in tests/sparse_cones.txt; planner should confirm whether sibling issue-1947 test files or eval_results/issue_1947 need lines too, per the registry's own conventions)

Scope / surfaces

• Primary target: tests/sparse_cones.txt
• Grep the workflow surface for the pattern before editing (grep -rln 'issue_1481' tests/sparse_cones.txt scripts/new_worktree.sh) 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; if workflow.yaml or CLAUDE.md change, they stay consistent with the rule file.
• This session runs under EPM_WORKFLOW_FIX_SESSION=1 and carries a workflow_fix_target: Provenance line — it MUST NOT auto-route any of its own subagents' workflow-fix candidates (recursion guard).

Provenance

• workflow_fix_target: tests/sparse_cones.txt
• fingerprint: 31e37654e526

Surfaced prose (verbatim, from the #2021 unit-A implementer manifest): "tests/test_issue1947_resume_matrix.py fails at COLLECTION in any sparse worktree lacking the eval_results/issue_1481 cone, and eval_results/issue_1481 is absent from tests/sparse_cones.txt — a pre-existing gap unrelated to this diff (I ran git -C "$WT" sparse-checkout add eval_results/issue_1481 locally; 16/16 passed). Unit B / the gate may hit this; the registry line is the documented fix."