lists: constant cards-per-row instead of measuring the grid

The adaptive grid resolves to exactly four cards on the TV's fixed full-
width pane — index % 4 needs no layout probing and cannot be skewed by
spanned items. Measuring existed only to re-derive the constant.

app/src/main/java/net/jeena/jtubetv/ui/screens/list/VideoListScreen.kt

@@ -91,20 +91,12 @@ fun VideoListScreen(
         LaunchedEffect(source) { viewModel.loadChannelHeader(AppGraph.repository) }
     }
 
-    // Cards-per-row of the adaptive grid — LEFT from the first card of ANY row
+    // Row starts of the 4-per-row grid: LEFT from a row's first card opens the
-    // must open the drawer (issue #7: "every time I'm all the way on the left").
+    // drawer (issue #7). rowCardWidth() sizes the adaptive columns to resolve
-    // Measure a CARD, not the first visible item: the page header spans the full
+    // to exactly 4 on the full-width TV pane, so the row start is index % 4 —
-    // width, and reading its width made cards-per-row = 1 — every card near the
+    // no layout measuring needed (measuring the first visible item instead was
-    // top then thought it was a row start and opened the drawer.
+    // what made the full-span page header count as "one card per row").
-    val cellsPerRow by remember {
+    val cardsPerRow = 4
-        androidx.compose.runtime.derivedStateOf {
-            val info = gridState.layoutInfo
-            val w = info.visibleItemsInfo
-                .firstOrNull { it.size.width < info.viewportSize.width }
-                ?.size?.width ?: 0
-            if (w > 0) (info.viewportSize.width / w).coerceIn(1, 10) else 0
-        }
-    }
 
     if (viewModel.loadingInitial && items.isEmpty()) {
         Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
@@ -170,7 +162,7 @@ fun VideoListScreen(
                 onClick = { lastOpenedIndex = index; onOpenVideo(video) },
                 showPrivacy = source is ListSource.MyVideos,
                 compact = true,
-                onLeftAtStart = if (index % cellsPerRow.coerceAtLeast(1) == 0) onOpenDrawer else null,
+                onLeftAtStart = if (index % cardsPerRow == 0) onOpenDrawer else null,
                 onUpToTopBar = upToTopBar?.takeIf { index < 4 },
                 modifier = Modifier
                     .focusRequester(fr),