Setup fix

[jugglingdev]

Added a composer setup script to clear config and cache to prevent caching issues when creating a new branch.

Made the Neon API variables nullable and created a private function to check that they are configured, which is called before the main fetch() function. Previously, there was a runtime error if those variables weren't configured which was preventing the composer config:clear and composer cache:clear commands from being run. Making them nullable stopped the runtime error and calling the private function ensures they are configured before making the API calls.

Also updated composer and npm.

[ThingEngineer]

Looks good! There were still a few issues though when starting up a fresh clone and since I cannot push commits to this PR so I created a follow up to this in PR #131 for these issues:

• make composer setup host-safe by avoiding DB-backed cache clearing during first-run setup making composer setup more idempotent across onboarding states (before and after Sail/DB availability)
• clarify the first-run onboarding order in the README
• align Sail and Composer on PHP 8.4 so containerized Composer and Artisan commands stop failing
• stop tracking generated bootstrap cache files that appear to have been committed before .gitignore was already excluding that folder