docs: SDK and embeddable score widget reference

[basanth-p]

Summary

Document the JavaScript SDK and embeddable score widget for developers who want to display a Patch ID score on their own portfolio or platform.

Content to cover

1. JavaScript SDK — install, initialise, fetch score
2. Embeddable widget — one-line <script> embed, customisation options
3. React component — <PatchIDScore userId="..." />
4. Styling / theming — CSS variables for dark/light mode
5. Privacy note — what data the widget collects

Deliverable

/sdks/overview.mdx and /sdks/score-widget.mdx

Depends on

• Score API live (patchid/core#10)