Document audio trace fields and verify diagnostic reads preserve jitter events

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallAudioTrace.kt

@@ -29,6 +29,8 @@ internal class CallAudioTrace(private val id: Long, private val emit: (String, S
     private var stoppedSince = -1L
     private var underrunAt = -10_000_000L
     private var faults = 0
+    private var reportedDeviceUnderruns = 0L
+    private var reportedJbUnderruns = 0L
 
     @Synchronized fun record(row: LongArray) {
         if (!enabled) return
@@ -51,6 +53,8 @@ internal class CallAudioTrace(private val id: Long, private val emit: (String, S
         if (!enabled) {
             history.clear(); summary.clear(); previous = null; eventAt = -1
             faults = 0; highSince = -1; stoppedSince = -1; underrunAt = -10_000_000
+            lastDump = -10_000_000; suppressed = 0
+            reportedDeviceUnderruns = 0; reportedJbUnderruns = 0
             return
         }
         if (overflow > 0) emit("WARN", "audio trace call=$id reporter overrun lost=$overflow")
@@ -108,10 +112,12 @@ internal class CallAudioTrace(private val id: Long, private val emit: (String, S
             "route=${last[1]}/${last[2]} min/avg/max queueUs=${range(::queued)} " +
             "jbMs=${range { it[16] + it[17] }} reserveMs=${range { it[18] }} spreadMs=${range { it[19] }} " +
             "pullUs=${range { it[5] }} writeUs=${range { it[6] }} wakeLateUs=${range { it[7] }} " +
-            "tempo=${last[21]} deviceUnderruns=${last[9]} jbUnderruns=${last[22]} " +
+            "tempo=${last[21]} deviceUnderruns=${last[9]} deviceUnderDelta=${last[9] - reportedDeviceUnderruns} " +
+            "jbUnderruns=${last[22]} jbUnderDelta=${last[22] - reportedJbUnderruns} " +
             "zeroWrites=${summary.sumOf { it[8] }} missingPcm=${summary.sumOf { (960 - it[20]).coerceAtLeast(0) }} " +
             "stamp=${last[12]}@${last[13]} readUs=${last[14]} ok=${last[15]} " +
             "buffer=${last[10]} start=${last[11]} fault=$faults suppressed=$suppressed")
+        reportedDeviceUnderruns = last[9]; reportedJbUnderruns = last[22]
         summary.clear()
     }