chore: scaffold docs site — structure, getting started, API reference baseline #1

What needs to be done?

Set up the public developer docs site at docs.patch-id.com.

Recommended stack

• Mintlify or Docusaurus — evaluate and pick one
• Custom domain: docs.patch-id.com

Initial content structure

Getting Started
  ├── What is Patch ID?
  ├── Quick start
  └── Authentication

API Reference
  ├── Overview
  ├── GET /score/{userId}
  ├── GET /profile/{userId}
  └── Webhooks

Integration Guides
  ├── Hiring platforms
  ├── DAOs
  └── Bootcamps

SDKs & Widgets
  ├── JavaScript SDK
  ├── Embeddable score widget
  └── React component

Acceptance criteria

• Site live at docs.patch-id.com
• Getting Started section complete
• API reference skeleton (endpoints defined, not all implemented)
• Linked from landing page and dashboard