v1.0.75: exclude Android app-private trees (Android/data,media,obb)

Scoped storage (Android 11+) lets a SAF grant LIST another app's
Android/media|data|obb dir but not OPEN the files, so every transfer there
failed and the pair was stuck reporting Partial forever (65 failures under
Android/media/com.whatsapp/ on Zahra). These hold app-managed data, not user
content, so exclude the whole subtree on both sides via path-prefix match in
isExcludedPath. ExcludePathTest covers the new prefixes + case-insensitivity.

app/src/test/kotlin/com/syncflow/domain/sync/ExcludePathTest.kt

@@ -57,6 +57,22 @@ class ExcludePathTest {
         assertTrue(isExcludedPath("a/b/.photo.jpg.sfpart", p))
     }
 
+    @Test fun `android app-private trees are excluded (scoped-storage unreadable)`() {
+        val p = pair()
+        assertTrue(isExcludedPath("Android/media/com.whatsapp/WhatsApp/Media/IMG.jpg", p))
+        assertTrue(isExcludedPath("Android/data/com.foo/files/x.bin", p))
+        assertTrue(isExcludedPath("Android/obb/com.game/main.obb", p))
+        assertTrue(isExcludedPath("android/MEDIA/com.x/y.jpg", p)) // case-insensitive
+    }
+
+    @Test fun `non-private Android paths are not excluded`() {
+        val p = pair()
+        // A user folder literally named "Android" at a deeper level is fine; only the
+        // top-level app-private trees are blocked.
+        assertFalse(isExcludedPath("DCIM/Android/holiday.jpg", p))
+        assertFalse(isExcludedPath("Pictures/android-wallpaper.png", p))
+    }
+
     @Test fun `normal media files are not excluded`() {
         val p = pair()
         assertFalse(isExcludedPath("DCIM/Camera/IMG_0001.jpg", p))