refactor: centralize playable media state

Move playback-related media state into shared model types and make the player consume a single PlayableMedia object instead of separately loading MediaItems, track preferences, resume positions, and media segments.

This updates PlayableMediaRepository to return playable media bundles, seeds the player playlist with the current item, keeps next-up entries in the same model, restores resume/segment handling, and fixes current queue highlighting.

The change also moves track preference models into core-model, centralizes Jellyfin BaseItemDto conversion, removes placeholder movie audio/subtitle fields, bumps the offline Room schema, and updates mobile/TV queue UI code for the playlist model.

Verification:
./gradlew --no-daemon :core-model:compileDebugKotlin :core:compileDebugKotlin :data:compileDebugKotlin :app:compileDebugKotlin

core-model/build.gradle.kts

@@ -1,13 +1,30 @@
 plugins {
-    id("java-library")
-    alias(libs.plugins.kotlin.jvm)
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.android)
+    alias(libs.plugins.kotlin.serialization)
 }
-java {
-    sourceCompatibility = JavaVersion.VERSION_11
-    targetCompatibility = JavaVersion.VERSION_11
-}
-kotlin {
-    compilerOptions {
-        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_11
+
+android {
+    namespace = "hu.bbara.purefin.model"
+    compileSdk = 36
+
+    defaultConfig {
+        minSdk = 29
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 }
+
+kotlin {
+    compilerOptions {
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_11)
+    }
+}
+
+dependencies {
+    implementation(libs.media3.common)
+    implementation(libs.kotlinx.serialization.json)
+}