Cursor: resolve binary-policy blocker and submit WinUI plugin

Summary

Tracks the Cursor submission workstream from #158 / MARKETPLACE-DISTRIBUTION.md. Cursor is next in the submission order after GitHub Copilot (done) and Claude Code (submitted, pending review).

Current state (verified 2026-09-09)

• No .cursor-plugin/marketplace.json exists anywhere in the repo yet (greenfield).
• plugins/winui/agent-plugin/skills/winui-dev-workflow/analyzer/Microsoft.WindowsAppSDK.Analyzers.dll is still bundled in the portable package.

Blocker

Cursor'"'"'s marketplace security policy states listed plugins must not ship binaries (see https://cursor.com/help/security-and-privacy/marketplace-security). The bundled analyzer .dll makes the current portable package ineligible.

Resolution options (pick one, record the decision here):

1. Produce a binary-free Cursor distribution (strip/replace the DLL in the Cursor-facing skill copy).
2. Replace the embedded payload with a signed tool resolved from a trusted package registry (e.g. NuGet) instead of bundling it in the repo.
3. Obtain written guidance from Cursor documenting an accepted alternate distribution model.

Do not submit the current binary-bearing package and assume an exception.

Submission work (once the blocker is resolved)

• Decide skills-only (plugins/winui/agent-plugin, no winui-dev custom agent) vs. full-parity native adapter (plugins/winui/.cursor-plugin/plugin.json + repo-root .cursor-plugin/marketplace.json).
• Add .cursor-plugin/marketplace.json pointing at the chosen source.
• If native: include display name, description, version, author/publisher, repository, license, keywords, category, component paths, relative logo path.
• Validate against Cursor'"'"'s published schema or the cursor/plugin-template validator.
• Test locally via ~/.cursor/plugins/local/winui; verify in Cursor'"'"'s Customize UI.
• Submit via https://cursor.com/marketplace/publish; confirm source branch/ref and update process during onboarding.
• Record listing URL and status back in #158.

References

• MARKETPLACE-DISTRIBUTION.md, "Cursor" section (PR #167)
• https://cursor.com/docs/reference/plugins#supported-plugin-formats
• https://cursor.com/marketplace/publish
• https://github.com/cursor/plugin-template

Tracked under #158.

Start with MARKETPLACE-DISTRIBUTION.md and inspect plugins/winui/agent-plugin/skills/winui-dev-workflow/analyzer/Microsoft.WindowsAppSDK.Analyzers.dll. Resolve the binary-policy question before choosing skills-only or native adapter packaging, then review the referenced Cursor schema and plugin-template validator. Done means a validated local plugin, a marketplace submission, and status recorded back in #158.