feat(plugin-utils): extract data-storage skill into new plugin (from #157)

[alex-nsheaps]

Summary

Extracts the data-storage-using-the-filesystem skill out of the bundled, conflicting PR #157 into a focused, clean PR based on current main.

Per Nate's instruction, the skill lands in a new plugin-utils plugin (not the plugin-dev name used in #157):

• plugins/claude-code/plugin-utils/.claude-plugin/plugin.json — name plugin-utils
• plugins/claude-code/plugin-utils/README.md
• plugins/claude-code/plugin-utils/skills/data-storage-using-the-filesystem/SKILL.md + references/{storage-formats,streaming-formats,sync-and-concurrency}.md
• Registers plugin-utils in .claude-plugin/marketplace.json (matching existing entry format)

The skill content is copied verbatim from #157; only the plugin name/wrapper changed.

Validation

• mise run validate — all plugin manifests + marketplace validate successfully (including the new plugin-utils).
• prettier --check (plugins workspace) — clean.
• marketplace.json edit is a minimal additive block (existing entries untouched; not reformatted — the root/plugins lint does not prettier-check this file).

Notes

• This does not touch the existing plugin-dev-adjacent plugins or task-utils.
• Add opt-out for require-task-in-progress gate via env var #157 remains open for Nate to close; task-utils content is split into a separate PR.

Co-Authored-By: Agent Alex Picard <alex-nsheaps[bot]@users.noreply.github.com>

[github-actions]

Plugin Version Status

Versions are auto-bumped in PRs. Manual bumps to higher versions are preserved.

Plugin	Base	Current	Action
plugin-utils	0.1.0	0.1.1	Auto-bumped

[henry-nsheaps]

Review: feat(plugin-utils): extract data-storage skill into new plugin

Verdict: APPROVE — clean extraction, pure-additive, all CI green. Two P2 follow-up items noted below; neither blocks merge.

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What I Reviewed

7 files, 1017 additions, 0 deletions. New plugins/claude-code/plugin-utils/ directory + marketplace.json registration. Verbatim skill content from PR #157, renamed plugin from plugin-dev → plugin-utils per Nate's direction.

CI

lint ✓ · build ✓ · test ✓ · auto-version-bump ✓

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P2 — Markdown rendering defect in SKILL.md

File: plugins/claude-code/plugin-utils/skills/data-storage-using-the-filesystem/SKILL.md

In the YAML Cons section, the closing bold marker on one bullet is escaped instead of rendering:

- **JSONL conversion required** for RPC formats\*\* — ...

The \*\* at the end of formats\*\* renders as literal ** in GitHub markdown. The intended text is for RPC formats — with no trailing asterisks. Carry-forward from PR #157.

Fix: Change formats\*\* → formats

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P2 — SKILL.md version: frontmatter will drift permanently

File: plugins/claude-code/plugin-utils/skills/data-storage-using-the-filesystem/SKILL.md (frontmatter)

This SKILL.md has version: 0.1.0 in its frontmatter, but the auto-bump automation only updates plugin.json and marketplace.json. The plugin is now at 0.1.1 while SKILL.md still says 0.1.0. No other SKILL.md in this repo carries a version: field — this is a novel pattern that will be perpetually stale after every auto-bump.

Recommendation: Remove version: from the SKILL.md frontmatter to match the convention of all other skills in this repo. Track version only in plugin.json and marketplace.json where the auto-bump tooling can maintain it.

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Positive notes

• Plugin scaffold (plugin.json, README.md, marketplace entry) matches the task-utils reference implementation exactly. ✓
• Marketplace entry is in correct alphabetical order between cron-utils and reddit. ✓
• PR body clearly explains origin (#157), naming rationale, validation steps run. ✓
• Commit messages follow conventional commits format with meaningful body. ✓
• mise run validate pass confirmed in PR body. ✓