Summary

• Add a fullstack SvelteKit walkthrough at docs-content/getting-started/fullstack-frameworks/sveltekit.md
• Documents server-side error monitoring using @highlight-run/node in hooks.server.ts
• Covers handleError hook, handle hook for request tracing, and manual error reporting in API routes
• Follows the same pattern as the existing Remix walkthrough

Closes #8032

/claim #8032

Details

The existing SvelteKit documentation only covers client-side instrumentation (hooks.client.ts). This PR adds a complete fullstack walkthrough that covers:

1. Client instrumentation - H.init() in hooks.client.ts for session replay and frontend errors
2. Server instrumentation - @highlight-run/node in hooks.server.ts for backend error monitoring
3. Error handling - Using SvelteKit’s handleError hook to report errors with session correlation
4. Request tracing - Optional handle hook wrapping for request-level visibility
5. API route errors - Manual error reporting in +server.ts routes
6. Logging - Automatic console log capture via the Node SDK
7. Verification - Steps to confirm both client and server instrumentation

Test plan

• Verify the markdown renders correctly in the docs site
• Confirm all code examples use correct SvelteKit and Highlight SDK APIs
• Check links to SvelteKit docs and Highlight docs resolve properly