fix site upload body limit

[vigneshrajsb]

Summary

• Increase the framework request body clone limit for multipart site uploads.
• Add a regression test for the upload-related framework configuration.

Validation

• pnpm run lint
• pnpm exec jest next.config.test.js --runInBand
• pnpm run ts-check was attempted; it fails on existing base-branch type errors.
• pnpm test was attempted; it requires local database configuration and the same failure was reproduced on the base branch.