Recognize shared preview sources and model texture cleanup failures

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

@@ -107,8 +107,10 @@ class StreamCaptureEngine(
     fun start() {
         preview.bind { target ->
             if (!handler.post {
+                if (target?.released == true) { LogManager.addLog("WARN", "video", "cancelled preview command id=$id"); return@post }
                 if (stopping || stopped || terminalFailure) { target?.release(); return@post }
-                if (target === previewTarget) { target?.release(); return@post }
+                if (target == null && previewTarget == null) return@post
+                if (target?.sameSource(previewTarget) == true) { target.release(); return@post }
                 val previous = previewTarget; previewTarget = target; previous?.release()
                 val config = activeConfig; val device = camera
                 LogManager.videoTrace("preview output change id=$id target=${target?.let(System::identityHashCode)} " +

tools/chatgui-android/video-tests/src/main/kotlin/android/graphics/SurfaceTexture.kt

@@ -0,0 +1,14 @@
+package android.graphics
+
+/** Только JVM: физический texture descriptor и отказ до/после release. */
+class SurfaceTexture(val id: Int) {
+    var released = false
+        private set
+    var releaseCalls = 0
+        private set
+    var failures = emptySet<String>()
+    fun release() {
+        releaseCalls++; check("release" !in failures) { "texture release failed" }
+        released = true; check("release after" !in failures) { "texture release failed after effect" }
+    }
+}

tools/chatgui-android/video-tests/src/main/kotlin/android/view/Surface.kt

@@ -1,7 +1,8 @@
 package android.view
 
 /** Только дескриптор вывода; реальных EGL/TextureView/драйверов нет. */
-class Surface {
+class Surface() {
+    constructor(texture: android.graphics.SurfaceTexture) : this()
     @Volatile var isValid = true
     var releaseCalls = 0
         private set