feat: add HAX CLI Claude Code plugin + marketplace

[rickmanelius]

Description of Changes

Adds an official Claude Code plugin for the HAX CLI, and turns this repo into a Claude Code plugin marketplace so it can be installed directly.

What changed

• Marketplace (.claude-plugin/marketplace.json) — registers haxtheweb as a plugin marketplace exposing the hax plugin.
• hax plugin (plugins/hax/):
  • Auto-install hook — a SessionStart hook checks for hax on PATH and installs @haxtheweb/create globally once if missing (opt out with HAX_PLUGIN_NO_AUTOINSTALL=1).
  • hax skill — full command-surface knowledge (web components, sites, content/node ops, imports, skeletons, publishing) plus HAX conventions (JavaScript-only, DDD design tokens, haxProperties), loaded automatically when HAX comes up.
  • Slash commands for the top workflows: /hax:quickstart, /hax:site, /hax:webcomponent, /hax:audit, /hax:serve, /hax:publish.
• Requirements doc (docs/) — the v1 requirements that scoped this work.

Why this change was needed

Lets users install and drive the HAX CLI from inside Claude Code with a golden-path onboarding (/hax:quickstart → scaffold a HAXsite, serve it, hand back a live URL) instead of learning the CLI surface by hand.

How to test

1. /plugin marketplace add haxtheweb/create (or a local checkout path)
2. /plugin install hax@haxtheweb
3. Start a new session and confirm the auto-install hook puts hax on PATH (or that it's skipped with HAX_PLUGIN_NO_AUTOINSTALL=1).
4. Run /hax:quickstart and confirm it scaffolds a HAXsite, serves it, and returns a live URL.

Notes

• Additive only — 13 new files, no changes to existing CLI code.
• The plugin pins to the published @haxtheweb/create package.

[github-actions]

All contributors have signed the CLA. Thank you!
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[rickmanelius]

I have read the CLA Document and I hereby sign the CLA

[rickmanelius]

It looks like my Compound Engineering work pulled over, which is probably not necessary.

I'd also like to run a more comprehensive set of tests off this fork/branch before this is merged, but I wanted to open it now in case there's any initial feedback.

[btopro]

This appears to provide at least some level of overlapping capability with https://github.com/haxtheweb/claudehax though I believe your work is more developer focused (which we need!) and @djfusco is more 'get commands good enough so we can do education stuff' focused. Please review and correct me if I'm wrong. Thank you for the contribution in advance Rick :)

[Copilot]

Pull request overview

Adds a Claude Code plugin marketplace entry for this repo and ships an initial hax plugin that helps users install and use the HAX CLI (@haxtheweb/create) via a SessionStart hook, an onboarding skill, and several /hax:* slash commands.

Changes:

• Adds a Claude Code plugin marketplace definition exposing the hax plugin.
• Introduces the hax plugin manifest, SessionStart auto-install hook, and user-facing README.
• Adds a HAX CLI skill plus slash-command docs for quickstart/site/webcomponent/audit/serve/publish workflows, and a requirements doc under docs/.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
.claude-plugin/marketplace.json	Registers the haxtheweb marketplace and exposes the hax plugin source path.
plugins/hax/.claude-plugin/plugin.json	Defines the hax plugin manifest metadata (name, version, links, keywords).
plugins/hax/README.md	Documents plugin purpose, installation via marketplace, and the /hax:quickstart golden path.
plugins/hax/hooks/hooks.json	Configures the SessionStart hook that runs the CLI availability/auto-install script.
plugins/hax/hooks/scripts/ensure-hax.sh	Implements best-effort detection/auto-install of @haxtheweb/create when hax is missing.
plugins/hax/skills/hax/SKILL.md	Provides the assistant with HAX CLI command-surface knowledge and HAX ecosystem conventions.
plugins/hax/commands/quickstart.md	Defines the /hax:quickstart workflow doc (scaffold site → serve).
plugins/hax/commands/site.md	Defines the /hax:site workflow doc for creating/administering HAXsites.
plugins/hax/commands/webcomponent.md	Defines the /hax:webcomponent workflow doc for scaffolding Lit/DDD components.
plugins/hax/commands/audit.md	Defines the /hax:audit workflow doc for DDD compliance auditing.
plugins/hax/commands/serve.md	Defines the /hax:serve workflow doc for running the HAXsite dev server.
plugins/hax/commands/publish.md	Defines the /hax:publish workflow doc for deploy/CI setup commands.
docs/brainstorms/2026-06-29-hax-onboarding-plugins-requirements.md	Captures v1 requirements and intended onboarding funnel/golden-path behavior.

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[btopro]

@rickmanelius This looks good to me as far as direction and getting hax into more ecosystems. haxtheweb/issues#2932 will help set the stage for this being accepted / modified to align with other skills we have hanging out there.