Fix playListNumber to stream-name mapping; add JavaFX ui module

- Playlist.streamForPlayListNumber maps the 1-based playListNumber to the
  actual stream entry; stream names are not sequential across discs
  (The Dark Knight: 00001/00003/00004; The Day After Tomorrow has
  duplicate 00002 names).
- CLI menu playback now resolves the correct .MPS file for every region.
- ui module: JavaFX via org.openjfx.javafxplugin + PlayerApp smoke test
  (window verified on this display).
- Validated menus + playback on 4 discs: Batman Begins (USA), Jackass
  (Australia), The Dark Knight (Europe), The Day After Tomorrow (Japan).

ui/build.gradle.kts

@@ -1,5 +1,6 @@
 plugins {
-    `java-library`
+    application
+    id("org.openjfx.javafxplugin") version "0.1.0"
 }
 
 java {
@@ -7,3 +8,16 @@ java {
         languageVersion = JavaLanguageVersion.of(21)
     }
 }
+
+javafx {
+    version = "21.0.5"
+    modules("javafx.controls")
+}
+
+application {
+    mainClass = "dev.quoije.umd.ui.PlayerApp"
+}
+
+dependencies {
+    implementation(project(":core"))
+}