[infra] spec.md `<!-- @trace -->` blocks lack auto-update mechanism (tangential from #154 plan)

[kiki830621]

Problem

Source: surfaced during /idd-plan #154 tangential sweep (Step 2.5)

openspec/specs/append-vs-modify-discipline/spec.md 每個 Requirement 後面都有 <!-- @trace --> block:

<!-- @trace
source: add-action-scoped-modify-discipline
updated: 2026-05-25
code:
  - plugins/issue-driven-dev/skills/idd-diagnose/SKILL.md
  - plugins/issue-driven-dev/skills/idd-issue/SKILL.md
  - plugins/issue-driven-dev/CHANGELOG.md
  - plugins/issue-driven-dev/skills/idd-update/SKILL.md
  ... (10+ files listed)
-->

8+ blocks in 1 spec,都列同樣 code: array of files。

Background

#150 spectra-archive 階段 emit 這些 trace blocks 作為 spec → code traceability hint。 但 grep 確認沒有自動更新機制:

$ grep -r "trace.*update\|update.*trace" .agents/ .claude/ scripts/ 2>/dev/null
# (no matches)

當未來 PR(例 #154)改 3 個 SKILL.md 但 <!-- @trace --> blocks 沒對應更新 → blocks become stale → reverse-lookup「該 spec Requirement 對應哪些 code 檔」不可靠。

Impact

每次任何 PR 動到 spec-linked 檔案,都該 review 是否有對應 <!-- @trace --> block 需 sync。 目前是 silent drift — 沒人警告。

Open questions

• spectra tooling(spectra validate / spectra analyze / 其他 subcommand)是否 native 支援 trace block auto-update?
• 若 spectra 不支援:寫 manual script(scripts/sync-spec-traces.sh)?或 pre-commit hook?
• block schema(source: updated: code:)是 [META] Codify append-vs-modify discipline as plugin-level principle #150 ship 還 spectra 內建?該設 contract 還是 informal?

Type

enhancement / infrastructure — spec-code traceability mechanism gap

Priority

P3 — parking-lot until ≥1 incident「spec ref'd file 已 rename/delete 但 trace block 沒跟」surfaces。 目前 silent drift 不阻擋 review。

Related

• [feature] /idd-edit runtime enforcement — proper proposal after 3-iteration bash failure (R1/R2/R3 on #153) #154 (idd-edit runtime enforcement) — will change 3 SKILL.md without updating trace blocks (Plan Out-of-scope explicit)
• [META] /idd-edit + IDD skills: bash vs alternative layer for strict flag parsing (sister concern from #154) #155 / [infra] IDD plugin test framework — adversarial fixtures for SKILL.md regression coverage (sister concern from #154) #156 sister concerns

Refs #154 #150