Found by dogfooding on nuwayze: `pipe queries lib` from the repo root
failed with
no resolved package graph at .dart_tool/package_config.json
remedy: run `flutter pub get` or `dart pub get` in .../nuwayze-w3/lib
It failed even with the package resolved, because the path was taken
as the project root: pipe looked for lib/.dart_tool/package_config.json,
which never exists, and the remedy sent the user to run pub get in a
directory that has no pubspec.
enclosingPackage() (project.dart) splits a path into the package that
contains it (the path itself when it holds a pubspec.yaml, else the
nearest ancestor that does) and the directory it names under that
root. `pipe queries` loads the package root and scans only that
directory, so `pipe queries lib/services` is `--dir lib/services` on
the package; an explicit --dir with such a path is relative to it.
Without a resolved graph the error now names the package root.
loadProject's own remedy uses the same lookup, so `pipe check lib`
(and the other commands, which still take the path as the root) now
says the path is inside the package at <root> and suggests passing
that with `--dir lib`, instead of pub get in lib.
Tests: enclosingPackage on a root, a nested directory, a nested
package and a missing path; loadProject's remedy for a directory
inside a package; and `pipe queries` on the fixture's lib/data
(root reported as the package, one file discovered), with
`lib --dir data`, and on an unresolved package where the remedy names
the root, not lib.
On nuwayze-w3: `pipe queries lib` exits 0 with 313 queries over 847
files, identical to `pipe queries .`; `pipe queries lib/services` scans
161 files and every one of its 212 queries sits under lib/services.
233 tests pass.
