all: fix version-specific issues

Fix a few version-specific issues so that I don't make a critical
blunder like I did in 2.4.0.

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -104,6 +104,11 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
 
         binding.homeToolbar.setOnMenuItemClickListener(this@HomeFragment)
 
+        binding.homeIndexingContainer.setOnApplyWindowInsetsListener { v, insets ->
+            logD("do basics you retard")
+            insets
+        }
+
         updateTabConfiguration()
 
         // Load the track color in manually as it's unclear whether the track actually supports
@@ -129,6 +134,11 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
 
             TabLayoutMediator(binding.homeTabs, this, AdaptiveTabStrategy(context, homeModel))
                 .attach()
+
+            // ViewPager2 will nominally consume window insets, which will then break the window
+            // insets applied to the indexing view before API 30. Fix this by overriding the
+            // callback with a no-op listener.
+            setOnApplyWindowInsetsListener { _, insets -> insets }
         }
 
         binding.homeFab.setOnClickListener { playbackModel.shuffleAll() }

app/src/main/java/org/oxycblt/auxio/music/MusicUtil.kt

@@ -69,14 +69,14 @@ val String.plainTrackNo: Int?
  * invalid.
  */
 val Int.packedTrackNo: Int?
-    get() = div(1000).nonZeroOrNull()
+    get() = mod(1000).nonZeroOrNull()
 
 /**
  * Parse out the disc number field as if the given Int is formatted as DTTT, where D Is the disc and
  * T is the track number. Values of zero will be ignored under the assumption that they are invalid.
  */
 val Int.packedDiscNo: Int?
-    get() = mod(1000).nonZeroOrNull()
+    get() = div(1000).nonZeroOrNull()
 
 /**
  * Parse out the number field from an NN/TT string that is typically found in DISC_NUMBER and

app/src/main/java/org/oxycblt/auxio/music/system/MediaStoreBackend.kt

@@ -454,6 +454,7 @@ class Api21MediaStoreBackend : MediaStoreBackend() {
 
         val rawTrack = cursor.getIntOrNull(trackIndex)
         if (rawTrack != null) {
+            logD(rawTrack)
             rawTrack.packedTrackNo?.let {
                 logD(it)
                 audio.track = it

app/src/main/res/layout/fragment_home.xml

@@ -52,7 +52,6 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_margin="@dimen/spacing_medium"
-            android:visibility="invisible"
             android:layout_gravity="center">
 
             <com.google.android.material.card.MaterialCardView
@@ -106,6 +105,7 @@
             </com.google.android.material.card.MaterialCardView>
 
         </org.oxycblt.auxio.home.EdgeFrameLayout>
+
     </FrameLayout>
 
     <org.oxycblt.auxio.home.EdgeFrameLayout