The table already computed and emitted the drop row for external URL
drops, but PlaylistView._on_files_dropped threw it away, so imported
files always appended. Thread it through: playlist_view.files_dropped
gains a row slot (None = append), MainWindow.import_files and
file_importer.import_paths take an optional position and hand it to
add_tracks_to_playlist, which already supported positional insert.
Files already in the library dedup to the existing track and insert at
the drop position without duplicating the library entry.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
trav
7e8359d872