feat: add `frontend-sveltekit` module

[ronak-create]

Summary

Add SvelteKit as a frontend option in the foundation create interactive prompt, alongside the existing frontend-svelte module.

Why

SvelteKit is the production framework for Svelte projects (routing, SSR, adapters) — analogous to how Next.js relates to React.
The current frontend-svelte module generates a plain Vite + Svelte app, which stops short of what most developers actually want.

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Files to generate

• src/routes/+page.svelte — root page component
• src/routes/+layout.svelte — root layout
• svelte.config.js — with @sveltejs/adapter-auto
• vite.config.ts
• tsconfig.json
• .env.example

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Implementation hints

• Add packages/modules/src/frontend/sveltekit.ts
  → copy svelte.ts as the starting point, swap the files array and package deps

• Register in:

  • index.ts
  • registry-loader.ts
  • graph-definition.ts
    under frontend choices

• Key dependencies:

  • @sveltejs/kit
  • @sveltejs/adapter-auto
  • svelte
  • vite

• Conflicts with:

  • frontend-svelte (same category)

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Contributor guidance

To better understand the implementation flow and module system, refer to:

➡️ CONTRIBUTING.md — especially the section on adding a new module

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Acceptance criteria

• foundation create lists SvelteKit as a frontend option
• Generated project runs vite dev without errors
• tsconfig.json includes .svelte-kit/tsconfig.json extend
• Snapshot test added in packages/modules