feat: album list, artist list, and artist detail views

- Fav albums: now shows a sortable list (title/artist/year/tracks);
  double-click opens the album
- Fav artists: now shows a sortable list; double-click opens the artist
- Artist detail page: name, biography summary, and their album list
- Rust ArtistDto gains albums field; get_artist fixed to extra=albums only
- Volume popup minimum width set so "100%" label is never clipped

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/view/artistview.hpp

@@ -0,0 +1,64 @@
+#pragma once
+
+#include "albumlistview.hpp"
+
+#include <QWidget>
+#include <QVBoxLayout>
+#include <QLabel>
+#include <QFont>
+#include <QJsonObject>
+#include <QJsonArray>
+
+/// Artist detail page: name, biography summary, and their album list.
+class ArtistView : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit ArtistView(QWidget *parent = nullptr) : QWidget(parent)
+    {
+        auto *layout = new QVBoxLayout(this);
+        layout->setContentsMargins(8, 8, 8, 8);
+        layout->setSpacing(6);
+
+        m_nameLabel = new QLabel(this);
+        QFont f = m_nameLabel->font();
+        f.setPointSize(f.pointSize() + 4);
+        f.setBold(true);
+        m_nameLabel->setFont(f);
+
+        m_bioLabel = new QLabel(this);
+        m_bioLabel->setWordWrap(true);
+        m_bioLabel->setAlignment(Qt::AlignTop | Qt::AlignLeft);
+        m_bioLabel->setMaximumHeight(80);
+
+        m_albums = new AlbumListView(this);
+
+        layout->addWidget(m_nameLabel);
+        layout->addWidget(m_bioLabel);
+        layout->addWidget(m_albums, 1);
+
+        connect(m_albums, &AlbumListView::albumSelected,
+                this, &ArtistView::albumSelected);
+    }
+
+    void setArtist(const QJsonObject &artist)
+    {
+        m_nameLabel->setText(artist["name"].toString());
+
+        const QString summary = artist["biography"].toObject()["summary"].toString();
+        m_bioLabel->setText(summary);
+        m_bioLabel->setVisible(!summary.isEmpty());
+
+        const QJsonArray albums = artist["albums"].toObject()["items"].toArray();
+        m_albums->setAlbums(albums);
+    }
+
+signals:
+    void albumSelected(const QString &albumId);
+
+private:
+    QLabel        *m_nameLabel = nullptr;
+    QLabel        *m_bioLabel  = nullptr;
+    AlbumListView *m_albums    = nullptr;
+};