fix(upgrade): Theme the upgrade retry button for its error card

The retry sits inside the errorContainer card but drew itself with the
default primary-on-surface outlined colors, which clashes with the card and
loses contrast once the tap latch disables it. Content and border now follow
onErrorContainer, with a dimmed disabled pair, and both states get a
preview.

app/src/gplay/java/eu/darken/capod/common/upgrade/ui/UpgradeScreen.kt

@@ -5,12 +5,14 @@ import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
 import androidx.compose.animation.togetherWith
+import androidx.compose.foundation.BorderStroke
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.twotone.AutoAwesome
 import androidx.compose.material.icons.twotone.WarningAmber
 import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
@@ -397,6 +399,7 @@ private fun UpgradeOffersBox(
                 // the user re-run the offer queries instead of leaving a dead screen.
                 // No reset needed: this composable unmounts the moment the state leaves Unavailable.
                 var retryTapped by remember { mutableStateOf(false) }
+                val retryEnabled = !retryTapped
                 OutlinedButton(
                     // Guard inside the callback, not just via `enabled`: `enabled` only takes effect
                     // after recomposition, so two taps in the same frame would both fire.
@@ -406,10 +409,20 @@ private fun UpgradeOffersBox(
                             onRetry()
                         }
                     },
-                    enabled = !retryTapped,
+                    enabled = retryEnabled,
                     modifier = Modifier
                         .fillMaxWidth()
                         .testTag(UpgradeScreenTags.GPLAY_RETRY),
+                    // The button sits on the errorContainer card, so the default primary-on-surface
+                    // outlined colors read as a foreign element with poor contrast.
+                    colors = ButtonDefaults.outlinedButtonColors(
+                        contentColor = MaterialTheme.colorScheme.onErrorContainer,
+                        disabledContentColor = MaterialTheme.colorScheme.onErrorContainer.copy(alpha = 0.38f),
+                    ),
+                    border = BorderStroke(
+                        1.dp,
+                        MaterialTheme.colorScheme.onErrorContainer.copy(alpha = if (retryEnabled) 1f else 0.1f),
+                    ),
                 ) {
                     Text(stringResource(R.string.general_retry_action))
                 }

app/src/main/java/eu/darken/capod/common/upgrade/ui/UpgradeContent.kt

@@ -2,6 +2,7 @@ package eu.darken.capod.common.upgrade.ui
 
 import androidx.annotation.StringRes
 import androidx.compose.animation.animateContentSize
+import androidx.compose.foundation.BorderStroke
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -21,6 +22,8 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.twotone.ArrowBack
 import androidx.compose.material.icons.twotone.CheckCircle
+import androidx.compose.material.icons.twotone.WarningAmber
+import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.CardColors
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.CenterAlignedTopAppBar
@@ -28,6 +31,7 @@ import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ElevatedCard
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
@@ -639,3 +643,58 @@ internal fun UpgradeInlineStateCard(
         content()
     }
 }
+
+@Preview2
+@Composable
+private fun UpgradeInlineStateCardPreview() {
+    PreviewWrapper {
+        Column(modifier = Modifier.padding(16.dp)) {
+            UpgradeInlineStateCard(
+                title = "Offers unavailable",
+                body = "Google Play did not answer. This is usually temporary.",
+                icon = Icons.TwoTone.WarningAmber,
+            ) {
+                OutlinedButton(
+                    onClick = {},
+                    modifier = Modifier.fillMaxWidth(),
+                    colors = ButtonDefaults.outlinedButtonColors(
+                        contentColor = MaterialTheme.colorScheme.onErrorContainer,
+                        disabledContentColor = MaterialTheme.colorScheme.onErrorContainer.copy(alpha = 0.38f),
+                    ),
+                    border = BorderStroke(1.dp, MaterialTheme.colorScheme.onErrorContainer),
+                ) {
+                    Text("Retry")
+                }
+            }
+        }
+    }
+}
+
+// The latched state the card shows after the retry was tapped: the contrast of a DISABLED button on
+// errorContainer is the part the default theming gets wrong, so it needs its own preview.
+@Preview2
+@Composable
+private fun UpgradeInlineStateCardDisabledActionPreview() {
+    PreviewWrapper {
+        Column(modifier = Modifier.padding(16.dp)) {
+            UpgradeInlineStateCard(
+                title = "Offers unavailable",
+                body = "Google Play did not answer. This is usually temporary.",
+                icon = Icons.TwoTone.WarningAmber,
+            ) {
+                OutlinedButton(
+                    onClick = {},
+                    enabled = false,
+                    modifier = Modifier.fillMaxWidth(),
+                    colors = ButtonDefaults.outlinedButtonColors(
+                        contentColor = MaterialTheme.colorScheme.onErrorContainer,
+                        disabledContentColor = MaterialTheme.colorScheme.onErrorContainer.copy(alpha = 0.38f),
+                    ),
+                    border = BorderStroke(1.dp, MaterialTheme.colorScheme.onErrorContainer.copy(alpha = 0.1f)),
+                ) {
+                    Text("Retry")
+                }
+            }
+        }
+    }
+}