fix: make parseHexColor crash-safe, clean up imports in EventCard

composeApp/src/commonMain/kotlin/ch/parano/myice/ui/components/EventCard.kt

@@ -1,6 +1,7 @@
 package ch.parano.myice.ui.components
 
 import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -13,7 +14,6 @@ import androidx.compose.material3.Card
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
@@ -47,7 +47,7 @@ fun EventCard(
                 modifier = Modifier
                     .padding(16.dp)
                     .fillMaxHeight(),
-                verticalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(4.dp),
+                verticalArrangement = Arrangement.spacedBy(4.dp),
             ) {
                 Text(
                     text = "${event.agegroup} - ${event.name}",
@@ -74,8 +74,7 @@ fun EventCard(
     }
 }
 
-private fun parseHexColor(hex: String): Color {
-    val cleanHex = hex.removePrefix("#")
-    val value = cleanHex.toLong(16)
+private fun parseHexColor(hex: String): Color? {
+    val value = hex.removePrefix("#").toLongOrNull(16) ?: return null
     return Color(0xFF000000 or value)
 }