Add review of centrally managed settings for marketplace plugins

[n2parko]

Summary

• review the current Cursor Marketplace plugin catalog and recurring component patterns
• document which plugin configuration surfaces should be managed centrally for team setup
• add a broad mock JSON file that flags which marketplace plugins likely require custom setup
• add a focused top-partner settings spec for Datadog, Linear, AWS, Stripe, Figma, and Notion with a clear shared-vs-user auth model and setup field recommendations

Testing

• parsed team-plugin-custom-settings.mock.json with Python json.loads to verify valid JSON
• verified the broad mock file includes 72 plugin decisions and reusable profile groupings
• parsed top-partner-plugin-settings.spec.json with Python json.loads
• verified the focused spec contains 6 plugins with the expected auth split: shared team auth for Datadog and AWS, user OAuth for Linear, Stripe, Figma, and Notion