Disable customized fetch intervals for stable builds for now

Until some of the issues get ironed out.

app/src/main/java/eu/kanade/presentation/manga/components/MangaDialogs.kt

@@ -19,6 +19,8 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.DpSize
 import androidx.compose.ui.unit.dp
+import eu.kanade.tachiyomi.util.system.isDevFlavor
+import eu.kanade.tachiyomi.util.system.isPreviewBuildType
 import kotlinx.collections.immutable.toImmutableList
 import tachiyomi.domain.manga.interactor.FetchInterval
 import tachiyomi.i18n.MR
@@ -72,13 +74,12 @@ fun SetIntervalDialog(
     val nextUpdateDays = remember(nextUpdate) {
         return@remember if (nextUpdate != null) {
             val now = Instant.now()
-            now.until(nextUpdate, ChronoUnit.DAYS).toInt()
+            now.until(nextUpdate, ChronoUnit.DAYS).toInt().coerceAtLeast(0)
         } else {
             null
         }
     }
 
-    // TODO: selecting "1" then doesn't allow for future changes unless defaulting first?
     AlertDialog(
         onDismissRequest = onDismissRequest,
         title = { Text(stringResource(MR.strings.pref_library_update_smart_update)) },
@@ -104,7 +105,8 @@ fun SetIntervalDialog(
                     Spacer(Modifier.height(MaterialTheme.padding.small))
                 }
 
-                if (onValueChanged != null) {
+                // TODO: selecting "1" then doesn't allow for future changes unless defaulting first?
+                if (onValueChanged != null && (isDevFlavor || isPreviewBuildType)) {
                     Text(stringResource(MR.strings.manga_interval_custom_amount))
 
                     BoxWithConstraints(

app/src/main/java/eu/kanade/presentation/manga/components/MangaInfoHeader.kt

@@ -182,7 +182,7 @@ fun MangaActionRow(
     val nextUpdateDays = remember(nextUpdate) {
         return@remember if (nextUpdate != null) {
             val now = Instant.now()
-            now.until(nextUpdate, ChronoUnit.DAYS).toInt()
+            now.until(nextUpdate, ChronoUnit.DAYS).toInt().coerceAtLeast(0)
         } else {
             null
         }