feat(slint): dedicated For You view with artist sections

Replaces the ad-hoc For You (a single album set crammed into
HomeState.sections) with a dedicated, ordered ForYouView/ForYouState
so the tab can mix album, track, and artist carousels — closer to
Tauri's For You. Lazy-loaded once on first open.

Sections (all reuse existing cards, no new card components):
  - Release Watch (album Carousel) — get_release_watch.
  - Recently Played Tracks (SlimCarousel) — local play-history.
  - Recently Played Albums (album Carousel) — local play-history.
  - Your Top Artists (ArtistCarousel) — the user's favorite artists
    via get_favorites.
  - Artists to Follow (ArtistCarousel) — similar artists seeded from
    a few favorites via get_similar_artists, excluding ones already
    followed (Follow chip shown).

Plumbing:
  - crate::foryou controller (load/apply/artwork). Five ForYou
    artwork targets feed the dedicated models.
  - select_tab("forYou") clears HomeState.sections (the home-content
    `for` renders nothing) and the For You content comes from
    ForYouView; HomeView routes the For You tab to ForYouView and
    gains an open-artist callback (wired through AppShell).
  - ensure_for_you_loaded lazy-loads on tab open (pill, header
    dropdown, and back/forward history).
  - home.rs no longer builds a For You section set (removed the
    redundant release-watch/favorites fetch on every home load).

Still to come (next increments): Qobuz Mixes row, Radio Stations
(old card design), Spotlight hero, and the reco-DB sections (More
from library, Rediscover) — those need backend the MVP lacks or the
mix detail views.

cc

crates/qbz-slint/ui/discover/HomeView.slint

@@ -12,6 +12,7 @@ import { HomeState, HomeActions, GenreFilterState, NavState, ContentView } from
 import { Carousel } from "Carousel.slint";
 import { SlimCarousel } from "SlimCarousel.slint";
 import { HomeSkeleton } from "HomeSkeleton.slint";
+import { ForYouView } from "ForYouView.slint";
 import { GenreFilterPopup } from "GenreFilterPopup.slint";
 import { QbzIcon } from "../primitives/QbzIcon.slint";
 import { NavButtons } from "../shell/NavButtons.slint";
@@ -141,6 +142,7 @@ component GearButton inherits Rectangle {
 
 export component HomeView inherits Rectangle {
     callback album-clicked(string);
+    callback open-artist(string);
     callback media-action(string, string, string);
 
     background: Theme.surface-main;
@@ -246,7 +248,9 @@ export component HomeView inherits Rectangle {
                 spacing: 40px;
                 alignment: start;
 
-                if HomeState.loading && HomeState.sections.length == 0: HomeSkeleton { }
+                if HomeState.active-tab != "forYou"
+                    && HomeState.loading
+                    && HomeState.sections.length == 0: HomeSkeleton { }
 
                 for section in HomeState.sections: Carousel {
                     section: section;
@@ -258,6 +262,23 @@ export component HomeView inherits Rectangle {
                     }
                 }
 
+                // For You renders its own ordered, heterogeneous
+                // sections from ForYouState.
+                if HomeState.active-tab == "forYou": ForYouView {
+                    open-album(id) => {
+                        root.album-clicked(id);
+                    }
+                    open-artist(id) => {
+                        root.open-artist(id);
+                    }
+                    media-action(kind, id, action) => {
+                        root.media-action(kind, id, action);
+                    }
+                    play-track(id) => {
+                        root.media-action("track", id, "play");
+                    }
+                }
+
                 // The Recently Played + Popular sections below belong
                 // to the Home tab only; Editor's Picks / For You show
                 // just their own cached section set above.