Prepare Cursor marketplace metadata

[Melbourneandrew]

Summary

• add Cursor marketplace author/display metadata for 8090 Solutions Inc.
• standardize the plugin license metadata and file on MIT
• update Cursor scaffold/schema support for displayName/license/logo fields
• document PR standards in AGENTS.md

Validation

• pnpm run validate
• pnpm run verify:software-factory
• pnpm run test
• pnpm run lint
• Cursor template validator: validation passed; only warning was missing hooks/hooks.json, which is expected because this plugin does not use hooks

Logo is intentionally not added yet; a follow-up can add the logo field once the asset/link is ready.