Add-to-playlist (Slices 0-3):
- qbz-core: check_playlist_duplicates + pure compute_playlist_duplicates
(reuses qbz_models::PlaylistDuplicateResult) + unit tests.
- PlaylistDuplicateConfirmModal (Add all / Add new only / Cancel); the
duplicate check runs on the Qobuz->Qobuz picker branch only (local/Plex
add directly, mirroring Tauri); the track-id Vec lives Rust-side in a
stash, never in Slint.
- Inline create-and-add in the picker (online create_playlist, offline ->
local playlist per D8) + client-side filter (Slint 1.16 has no string
contains, routed through a Rust callback) + success toasts.
Playlist importer (1:1 Tauri port):
- New headless crate qbz-playlist-import (Spotify/Apple/Tidal/Deezer
scrapers, Qobuz matcher, importer, progress sink, shared http client;
copy-not-move from src-tauri, zero tauri deps; 40 unit tests green).
- PlaylistImportModal (two-step fetch-preview -> import with live progress
bar / log / summary) + controller + sidebar PLAYLISTS menu entry point.
Reco logging staged behind TODO(reco-v1) markers (golden rule: playlist
recommendations ship in Slint v1 once the reco engine is extracted to a
shared crate).
cc
