Make NODE_BINARY discovery nvm-friendly for CI
Add nvm support to packages/app/ios/.xcode.env and ensure CI writes a local ios/.xcode.env.local with the actual node path (using which node) so Xcode script phases can find Node in nvm environments. Remove the previously committed hardcoded .xcode.env.local and drop a debug fastlane test step from .gitlab-ci.yml. This replaces the static /usr/local/bin/node path with dynamic discovery to avoid CI/Xcode build failures on runners using nvm.