feat(qbz-qt): phase 15 — search 1:1 (cortinilla + full page with filters)

Intelligent search engine reused from qbz_app (SWR cache, interaction
recording, rank_within, top_for_query; app-menu kill switch on the
shared pref). Header field fully live: 220ms debounce, keyboard
semantics (arrows/Enter/Esc), clear, idle-close. Cortinilla as a plain
overlay (pointer stays on the field — Slint's exact reason): top
result, spec-ordered sections with View more, skeleton, row activation
dispatches (album/artist views, track play). Search page: 5 searchType
filter radios (Main Artist/Performer/Composer/Label/Release Name),
5 scope tabs, Most-popular hero, carousels, per-type grids/lists with
paged Load more. Perf: cortinilla 245ms cached / 1.1s cold. Fixed an
artwork attach bug the screenshots exposed (url/path slot mixup).
18/18 tests.

km

crates/qbz-qt/qml/Main.qml

@@ -42,6 +42,7 @@ ApplicationWindow {
 
 
 
+
     Loader {
         id: screenLoader
         anchors.fill: parent