These files are regenerated by flutter pub get and contain machine-
specific paths (FLUTTER_ROOT, FLUTTER_APPLICATION_PATH). They should
not be tracked — the file header itself states "do not check into
version control".
- Update .gitignore: prepend **/ to .flutter-plugins-dependencies so
it matches in sub-packages, add Generated.xcconfig and
flutter_export_environment.sh patterns.
- git rm --cached the 4 files that were already tracked (keeps them
on disk for local builds but removes from repo).
The repo had no root-level .gitignore, so .dart_tool/, ephemeral plugin
symlinks and build artifacts were being tracked across the workspace.
Every flutter pub get regenerated them and they polluted PRs as recurring
noise.
- Add root .gitignore covering .dart_tool/, ephemeral plugin symlinks,
build/, coverage/, IDE files
- Untrack ~39 existing cache files across root, modules and packages
