feat: partial album split view + artist page full-screen + Bibliothek iTunes integration

- Partial album detail: tapping incomplete albums now shows downloaded songs
  (normal playback) above and missing iTunes tracks (30s preview + download)
  below — on both Android and web PWA
- Android: ItunesArtistScreen now renders full-screen above the tab/search bar
- Android: ArtistDetailScreen (Bibliothek) now loads iTunes data in parallel —
  adds Weltweit populär section and In Library/Unvollständig/Nicht heruntergeladen
  album sections identical to the Erkunden artist page
- Fix: artist no longer appears in its own Similar Artists row
- Fix: duplicate album entries deduplicated by collectionId in categorizeAlbums

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

android/gradle/libs.versions.toml

@@ -1,22 +1,80 @@
 [versions]
-agp = "8.13.2"
-kotlin = "1.9.23"
-coreKtx = "1.13.1"
-appcompat = "1.7.0"
-material = "1.12.0"
-media3 = "1.4.1"
-coroutines = "1.8.0"
+agp                  = "8.13.2"
+kotlin               = "2.1.20"
+composeBom           = "2024.12.01"
+coreKtx              = "1.13.1"
+appcompat            = "1.7.0"
+activityCompose      = "1.9.3"
+navigationCompose    = "2.8.3"
+lifecycleVm          = "2.8.7"
+media3               = "1.4.1"
+ktor                 = "2.3.12"
+kotlinxSerialization = "1.7.3"
+kotlinxCoroutines    = "1.9.0"
+room                 = "2.6.1"
+datastore            = "1.1.1"
+coil                 = "2.7.0"
+splashscreen         = "1.0.1"
 
 [libraries]
-androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
-androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
-material = { group = "com.google.android.material", name = "material", version.ref = "material" }
-media3-exoplayer = { group = "androidx.media3", name = "media3-exoplayer", version.ref = "media3" }
-media3-session = { group = "androidx.media3", name = "media3-session", version.ref = "media3" }
-media3-common = { group = "androidx.media3", name = "media3-common", version.ref = "media3" }
-media3-datasource = { group = "androidx.media3", name = "media3-datasource", version.ref = "media3" }
-kotlinx-coroutines-android = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "coroutines" }
+# AndroidX core
+androidx-core-ktx          = { group = "androidx.core",               name = "core-ktx",                 version.ref = "coreKtx" }
+androidx-appcompat         = { group = "androidx.appcompat",           name = "appcompat",                version.ref = "appcompat" }
+androidx-activity-compose  = { group = "androidx.activity",           name = "activity-compose",          version.ref = "activityCompose" }
+androidx-splashscreen      = { group = "androidx.core",               name = "core-splashscreen",         version.ref = "splashscreen" }
+
+# Compose BOM + core
+compose-bom        = { group = "androidx.compose",      name = "compose-bom",        version.ref = "composeBom" }
+compose-ui         = { group = "androidx.compose.ui",   name = "ui" }
+compose-ui-tooling = { group = "androidx.compose.ui",   name = "ui-tooling" }
+compose-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
+compose-foundation = { group = "androidx.compose.foundation", name = "foundation" }
+compose-material3  = { group = "androidx.compose.material3", name = "material3" }
+compose-icons      = { group = "androidx.compose.material", name = "material-icons-extended" }
+
+# Navigation
+navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
+
+# Lifecycle / ViewModel
+lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "lifecycleVm" }
+lifecycle-runtime-compose   = { group = "androidx.lifecycle", name = "lifecycle-runtime-compose",   version.ref = "lifecycleVm" }
+
+# Media3
+media3-exoplayer   = { group = "androidx.media3", name = "media3-exoplayer",       version.ref = "media3" }
+media3-session     = { group = "androidx.media3", name = "media3-session",         version.ref = "media3" }
+media3-common      = { group = "androidx.media3", name = "media3-common",          version.ref = "media3" }
+media3-datasource  = { group = "androidx.media3", name = "media3-datasource",      version.ref = "media3" }
+media3-ui          = { group = "androidx.media3", name = "media3-ui",              version.ref = "media3" }
+
+# Ktor (HTTP client)
+ktor-client-core         = { group = "io.ktor", name = "ktor-client-core",            version.ref = "ktor" }
+ktor-client-android      = { group = "io.ktor", name = "ktor-client-android",         version.ref = "ktor" }
+ktor-client-content-neg  = { group = "io.ktor", name = "ktor-client-content-negotiation", version.ref = "ktor" }
+ktor-serialization-json  = { group = "io.ktor", name = "ktor-serialization-kotlinx-json", version.ref = "ktor" }
+ktor-client-logging      = { group = "io.ktor", name = "ktor-client-logging",         version.ref = "ktor" }
+
+# Kotlinx
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerialization" }
+kotlinx-coroutines-android  = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "kotlinxCoroutines" }
+kotlin-reflect              = { group = "org.jetbrains.kotlin",  name = "kotlin-reflect",            version.ref = "kotlin" }
+
+# Room
+room-runtime  = { group = "androidx.room", name = "room-runtime", version.ref = "room" }
+room-ktx      = { group = "androidx.room", name = "room-ktx",     version.ref = "room" }
+room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
+
+# DataStore (settings / credentials)
+datastore-preferences = { group = "androidx.datastore", name = "datastore-preferences", version.ref = "datastore" }
+
+# Coil (image loading)
+coil-compose = { group = "io.coil-kt", name = "coil-compose", version.ref = "coil" }
+
+# Google Fonts (Outfit)
+compose-ui-google-fonts = { group = "androidx.compose.ui", name = "ui-text-google-fonts" }
 
 [plugins]
-android-application = { id = "com.android.application", version.ref = "agp" }
-kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
+android-application = { id = "com.android.application",             version.ref = "agp" }
+kotlin-android      = { id = "org.jetbrains.kotlin.android",        version.ref = "kotlin" }
+kotlin-compose      = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
+ksp                 = { id = "com.google.devtools.ksp",             version = "2.1.20-1.0.32" }