Fix JAR label matching: by language+codec for label format, by index for TextField

Labels like eng_MLP_ now match to the correct stream by checking language
and codec hint against the stream's properties. Fixes Barbie where labels
were swapped (TrueHD label was on DD stream). TextField format (Civil War)
still uses index matching.

TrackLabel now carries language + codec_hint for structured matching.

src/disc.rs

@@ -580,35 +580,63 @@ impl Disc {
     }
 
     /// Merge JAR labels into title streams.
-    /// Matches by position — JAR audio labels correspond to audio streams in order,
-    /// JAR subtitle labels correspond to subtitle streams in order.
+    ///
+    /// Two matching strategies:
+    /// 1. By language+codec (label format like eng_MLP_) — matches stream by content
+    /// 2. By index (TextField format) — Nth label → Nth stream
     fn apply_jar_labels(titles: &mut [Title], jar: &crate::jar::JarLabels) {
         if jar.audio.is_empty() && jar.subtitle.is_empty() {
             return;
         }
 
-        for title in titles.iter_mut() {
-            let mut audio_idx = 0;
-            let mut sub_idx = 0;
+        // Check if labels have language+codec info (label format)
+        let has_content_match = jar.audio.iter().any(|l| !l.language.is_empty() && !l.codec_hint.is_empty());
 
-            for stream in &mut title.streams {
-                match stream {
-                    Stream::Audio(a) => {
-                        if let Some(label) = jar.audio.get(audio_idx) {
-                            if !label.description.is_empty() {
-                                a.label = label.description.clone();
-                            }
+        for title in titles.iter_mut() {
+            if has_content_match {
+                // Match by language + codec
+                Self::apply_labels_by_content(title, jar);
+            } else {
+                // Match by index
+                Self::apply_labels_by_index(title, jar);
+            }
+        }
+    }
+
+    /// Match labels to streams by language + codec hint.
+    fn apply_labels_by_content(title: &mut Title, jar: &crate::jar::JarLabels) {
+        // For each JAR audio label, find the matching stream
+        let mut used = vec![false; jar.audio.len()];
+
+        for stream in &mut title.streams {
+            if let Stream::Audio(a) = stream {
+                // Find a JAR label matching this stream's language + codec
+                for (i, label) in jar.audio.iter().enumerate() {
+                    if used[i] { continue; }
+                    if label.language == a.language && codec_matches(&label.codec_hint, a.codec) {
+                        if !label.description.is_empty() {
+                            a.label = label.description.clone();
                         }
-                        audio_idx += 1;
+                        used[i] = true;
+                        break;
                     }
-                    Stream::Subtitle(_s) => {
-                        // TODO: JAR subtitle labels could set forced flag or description
-                        sub_idx += 1;
-                    }
-                    _ => {}
                 }
             }
-            let _ = sub_idx; // suppress warning
+        }
+    }
+
+    /// Match labels to streams by STN index position.
+    fn apply_labels_by_index(title: &mut Title, jar: &crate::jar::JarLabels) {
+        let mut audio_idx = 0;
+        for stream in &mut title.streams {
+            if let Stream::Audio(a) = stream {
+                if let Some(label) = jar.audio.get(audio_idx) {
+                    if !label.description.is_empty() {
+                        a.label = label.description.clone();
+                    }
+                }
+                audio_idx += 1;
+            }
         }
     }
 
@@ -892,6 +920,18 @@ fn session_read_sector(session: &mut DriveSession, lba: u32, buf: &mut [u8; 2048
 
 // ─── Format helpers ────────────────────────────────────────────────────────
 
+/// Check if a JAR codec hint matches a stream codec.
+fn codec_matches(hint: &str, codec: Codec) -> bool {
+    match hint {
+        "MLP" => codec == Codec::TrueHd,
+        "AC3" => codec == Codec::Ac3 || codec == Codec::Ac3Plus,
+        "DTS" => codec == Codec::Dts || codec == Codec::DtsHdMa || codec == Codec::DtsHdHr,
+        "LPCM" => codec == Codec::Lpcm,
+        "ADES" => codec == Codec::Ac3, // descriptive audio is usually DD
+        _ => false,
+    }
+}
+
 fn format_resolution(video_format: u8, _video_rate: u8) -> String {
     match video_format {
         1 => "480i".into(),