Add cursor plugin definitions

[ITaluone]

Publish Fallout.Workbench on the Cursor Marketplace

Add Cursor plugin manifests so this repo can be listed on the Cursor Marketplace. The existing Claude Code files stay as they are.
Cursor does not read .claude-plugin/. It reads .cursor-plugin/plugin.json for each plugin, and .cursor-plugin/marketplace.json at the repo root when one repo holds more than one plugin.

What changed

• .cursor-plugin/marketplace.json lists fallout-workbench (repo root) and fallout-core (plugins/fallout-core).
• .cursor-plugin/plugin.json is the manifest for the shared skills, the story-writer agent, and the new-issue command.
• plugins/fallout-core/.cursor-plugin/plugin.json is the manifest for the core-repo skills.
• commands/new-issue.md sets name: new-issue.
  patterns/ and antipatterns/ stay normal docs. Cursor does not load them as plugin parts.

Check it locally

Copy each plugin into %USERPROFILE%\.cursor\plugins\local\ (a real copy, not a symlink). Reload the window. Open Customize and confirm the skills, story-writer, and new-issue.
On an Enterprise plan, local imports can be turned off under Dashboard → Settings → Security & Identity → Marketplace and Plugins. If a marketplace plugin with the same name is already installed, that install is the one Cursor uses.

Publish on the public marketplace

The repo is already public and MIT licensed. Both are required.

1. Push the manifest files to main.
2. Open cursor.com/marketplace/publish.
3. Submit https://github.com/Fallout-build/Fallout.Workbench.
4. Wait for review. Cursor reviews the plugin before it is listed, and reviews each later update the same way. Pushing to GitHub does not update the listing. Ask Cursor to re-index after a change.
   People then install it from Customize, or from cursor.com/marketplace.

Publish for the Fallout team only

Use this when the plugin should stay inside the Fallout Cursor team. It does not put the plugin on the public marketplace. Team marketplaces need a Teams or Enterprise plan. On Enterprise, only an admin can add one.

1. Open Dashboard → Plugins & MCPs → Team Marketplaces → Add Marketplace.
2. Choose Import from Repo and paste https://github.com/Fallout-build/Fallout.Workbench.
3. Review the parsed plugins, set who can see the marketplace, and save.
   Set each plugin to Default Off (opt in), Default On (installed, can be turned off), or Required (installed, cannot be removed).
   Turn on Enable Auto Refresh so later commits are picked up. That needs the Cursor GitHub App on the repo. You can also press Refresh by hand.

Refs: Fallout-build/Fallout#712