feat(registry): add @sans to directory

[sansalgo]

Summary

• Adds @sans to the registry directory so npx shadcn add @sans/<item> resolves without manual components.json configuration.
• Registry endpoint is live at https://sans.sansorigin.com/r/{name}.json (verified registry.json and claude-spinner.json resolve correctly).

Test plan

• Confirmed https://sans.sansorigin.com/r/claude-spinner.json returns valid registry item JSON.
• Verified directory.json remains valid JSON and the new entry matches the existing schema (unique @ namespace, valid homepage/url with {name} placeholder, description, logo).

[vercel]

@sansalgo is attempting to deploy a commit to the shadcn-pro Team on Vercel.

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[shadcn]

Thanks for the contribution. This entry is included in #11861. Closing this PR in favor of the combined update.