Fixes #272

Fixes #265

Fixes #309 

Unfortunately a lot of React.js apps have this problem with peer deps
because older dependencies specify pre-v19. Because Dyad app templates
do (and should) explicitly specify React as a dependnecy, using
`--legacy-peer-deps` gives us the right behavior where it effectively
does not install peer deps and avoids the React version errors.

For pnpm, we have an explicit lockfiles for our templates so there isn't
an issue.

Context:
https://stackoverflow.com/questions/66239691/what-does-npm-install-legacy-peer-deps-do-exactly-when-is-it-recommended-wh

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Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>