* fix(scanner): respect FollowSymlinks in watcher-triggered scans
With FollowSymlinks disabled, creating a folder symlink inside the library
made the watcher schedule a selective scan with the link itself as the
target. walkDirTree only checked FollowSymlinks for child entries, so it
walked the link and imported its files as duplicates (or, for links that
point outside the library, files that should never be scanned).
walkDirTree now skips any target folder whose path, or any parent folder,
is a symlink when FollowSymlinks is disabled. The skipped target stays in
lastUpdates, so rows previously imported through it are marked missing,
matching what a full scan does. localFS now implements fs.ReadLinkFS so
fs.Lstat can see symlinks instead of following them.
Fixes#6292
* test(scanner): run the #6292 symlinked target tests on Windows
Remove the SkipOnWindows guard from the symlinked target folder tests, so
the go-windows CI job covers the FollowSymlinks fix for selective scans.
b78c963931