feat: pagination, back/forward nav, context menu, artist fav, image fix

**Artist portrait**
- Fix CDN URL: images.portrait.{hash,format} →
  https://static.qobuz.com/images/artists/covers/large/{hash}.{format}

**Section alignment**
- Qt::ToolButtonTextOnly on all section toggles so text is truly left-aligned

**Auth 401 race condition**
- qobuz_backend_set_token now uses blocking_lock() instead of spawning an
  async task, guaranteeing the token is set before any subsequent API call

**Pagination (infinite scroll)**
- Release sections load 50 at a time (was 500)
- ArtistSection tracks has_more + loaded count; scrolling to the bottom
  emits loadMoreRequested → ArtistView calls getArtistReleases(offset=N)
- AlbumListView gains addAlbums() for append; setReleases routes to
  setAlbums (offset=0) or appendAlbums (offset>0)

**Back/Forward navigation**
- MainToolBar exposes Back/Forward QActions (go-previous/go-next icons)
- MainWindow keeps a NavPage vector + index; pushNav() on every album/artist
  navigation; goBack/goForward re-navigate without pushing history

**Context menu on now-playing label**
- Right-click on track label in toolbar → "Go to Album" / "Go to Artist"
- MainToolBar stores current track; emits albumRequested/artistRequested
  signals wired to MainWindow's existing handlers

**Artist favourites button**
- ♡ Favourite / ♥ Favourited toggle in artist header
- Calls new addFavArtist / removeFavArtist (Rust + Qt backend wiring)

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

build-viz/qobuz-qt_autogen/AMGWBOP3ZU/moc_lastfm.cpp

@@ -0,0 +1,124 @@
+/****************************************************************************
+** Meta object code from reading C++ file 'lastfm.hpp'
+**
+** Created by: The Qt Meta Object Compiler version 69 (Qt 6.10.2)
+**
+** WARNING! All changes made in this file will be lost!
+*****************************************************************************/
+
+#include "../../../src/scrobbler/lastfm.hpp"
+#include <QtNetwork/QSslError>
+#include <QtCore/qmetatype.h>
+
+#include <QtCore/qtmochelpers.h>
+
+#include <memory>
+
+
+#include <QtCore/qxptype_traits.h>
+#if !defined(Q_MOC_OUTPUT_REVISION)
+#error "The header file 'lastfm.hpp' doesn't include <QObject>."
+#elif Q_MOC_OUTPUT_REVISION != 69
+#error "This file was generated using the moc from 6.10.2. It"
+#error "cannot be used with the include files from this version of Qt."
+#error "(The moc has changed too much.)"
+#endif
+
+#ifndef Q_CONSTINIT
+#define Q_CONSTINIT
+#endif
+
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_DEPRECATED
+QT_WARNING_DISABLE_GCC("-Wuseless-cast")
+namespace {
+struct qt_meta_tag_ZN15LastFmScrobblerE_t {};
+} // unnamed namespace
+
+template <> constexpr inline auto LastFmScrobbler::qt_create_metaobjectdata<qt_meta_tag_ZN15LastFmScrobblerE_t>()
+{
+    namespace QMC = QtMocConstants;
+    QtMocHelpers::StringRefStorage qt_stringData {
+        "LastFmScrobbler",
+        "onTrackStarted",
+        "",
+        "QJsonObject",
+        "track",
+        "onPositionChanged",
+        "positionSecs",
+        "onTrackFinished"
+    };
+
+    QtMocHelpers::UintData qt_methods {
+        // Slot 'onTrackStarted'
+        QtMocHelpers::SlotData<void(const QJsonObject &)>(1, 2, QMC::AccessPublic, QMetaType::Void, {{
+            { 0x80000000 | 3, 4 },
+        }}),
+        // Slot 'onPositionChanged'
+        QtMocHelpers::SlotData<void(quint64, quint64)>(5, 2, QMC::AccessPublic, QMetaType::Void, {{
+            { QMetaType::ULongLong, 6 }, { QMetaType::ULongLong, 2 },
+        }}),
+        // Slot 'onTrackFinished'
+        QtMocHelpers::SlotData<void()>(7, 2, QMC::AccessPublic, QMetaType::Void),
+    };
+    QtMocHelpers::UintData qt_properties {
+    };
+    QtMocHelpers::UintData qt_enums {
+    };
+    return QtMocHelpers::metaObjectData<LastFmScrobbler, qt_meta_tag_ZN15LastFmScrobblerE_t>(QMC::MetaObjectFlag{}, qt_stringData,
+            qt_methods, qt_properties, qt_enums);
+}
+Q_CONSTINIT const QMetaObject LastFmScrobbler::staticMetaObject = { {
+    QMetaObject::SuperData::link<QObject::staticMetaObject>(),
+    qt_staticMetaObjectStaticContent<qt_meta_tag_ZN15LastFmScrobblerE_t>.stringdata,
+    qt_staticMetaObjectStaticContent<qt_meta_tag_ZN15LastFmScrobblerE_t>.data,
+    qt_static_metacall,
+    nullptr,
+    qt_staticMetaObjectRelocatingContent<qt_meta_tag_ZN15LastFmScrobblerE_t>.metaTypes,
+    nullptr
+} };
+
+void LastFmScrobbler::qt_static_metacall(QObject *_o, QMetaObject::Call _c, int _id, void **_a)
+{
+    auto *_t = static_cast<LastFmScrobbler *>(_o);
+    if (_c == QMetaObject::InvokeMetaMethod) {
+        switch (_id) {
+        case 0: _t->onTrackStarted((*reinterpret_cast<std::add_pointer_t<QJsonObject>>(_a[1]))); break;
+        case 1: _t->onPositionChanged((*reinterpret_cast<std::add_pointer_t<quint64>>(_a[1])),(*reinterpret_cast<std::add_pointer_t<quint64>>(_a[2]))); break;
+        case 2: _t->onTrackFinished(); break;
+        default: ;
+        }
+    }
+}
+
+const QMetaObject *LastFmScrobbler::metaObject() const
+{
+    return QObject::d_ptr->metaObject ? QObject::d_ptr->dynamicMetaObject() : &staticMetaObject;
+}
+
+void *LastFmScrobbler::qt_metacast(const char *_clname)
+{
+    if (!_clname) return nullptr;
+    if (!strcmp(_clname, qt_staticMetaObjectStaticContent<qt_meta_tag_ZN15LastFmScrobblerE_t>.strings))
+        return static_cast<void*>(this);
+    return QObject::qt_metacast(_clname);
+}
+
+int LastFmScrobbler::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
+{
+    _id = QObject::qt_metacall(_c, _id, _a);
+    if (_id < 0)
+        return _id;
+    if (_c == QMetaObject::InvokeMetaMethod) {
+        if (_id < 3)
+            qt_static_metacall(this, _c, _id, _a);
+        _id -= 3;
+    }
+    if (_c == QMetaObject::RegisterMethodArgumentMetaType) {
+        if (_id < 3)
+            *reinterpret_cast<QMetaType *>(_a[0]) = QMetaType();
+        _id -= 3;
+    }
+    return _id;
+}
+QT_WARNING_POP