feat(qbz-qt): phase 13 — correct card families in Library + Discover tabs

Library audit: the phase-7 conversion never actually mounted the shared
AlbumCard — ALL kinds used the invented feed card. Now per-kind 1:1:
LibTrackCard (discover/TrackCard replica with wired next/later/queue
enqueue), shared AlbumCard for albums, LibArtistCard (ArtistGridCard
circle), LibPlaylistCard (collage, follow-aware), LibLabelCard
(gradient + contain-fit logo), list rows rewritten to the real
FavoritesView inline row, Tracks tab on a TrackRow replica. Discover:
Editor's Picks and For You tabs rendered from the same discover-index
fetch, prefs-ordered per DiscoverPrefsStore (incl. mostStreamed#album
variant, Qobuz Mixes gradient tiles, Pinned in the user's own position);
Recommendations tab gated on the user's pref with an explicit engine
placeholder. No refetch on tab switches.

km

crates/qbz-qt/qml/assets/icons/accent/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#4285f4" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/black/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#000000" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/favorite/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ef4444" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/muted/disc-3.svg

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+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#888888" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/primary/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/secondary/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#cccccc" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>

crates/qbz-qt/qml/assets/icons/warning/disc-3.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#fbbf24" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M6 12c0-1.7.7-3.2 1.8-4.2" />
+  <circle cx="12" cy="12" r="2" />
+  <path d="M18 12c0 1.7-.7 3.2-1.8 4.2" />
+  <circle cx="12" cy="12" r="10" />
+</svg>