fix: use composite key for CardInfo in HelpScreen grid (#244)

Multiple CardInfo entries can share the same nameRes (e.g., Troika has
both MifareClassic and MifareUltralight variants). Using nameRes.key
alone as the LazyVerticalGrid item key caused a duplicate key crash
when scrolling.

Add CardInfo.uniqueKey that combines nameRes.key with cardType.name,
and use it for grid keys and card selection in HelpScreen.

Co-authored-by: Claude <claude@codebutler.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: 3 people

app/src/commonMain/kotlin/com/codebutler/farebot/shared/ui/screen/HelpScreen.kt

@@ -280,14 +280,14 @@ fun ExploreContent(
                                 .padding(horizontal = 12.dp, vertical = 8.dp),
                     )
                 }
-                items(cards, key = { it.nameRes.key }) { card ->
+                items(cards, key = { it.uniqueKey }) { card ->
                     CardImageTile(
                         card = card,
                         cardName = cardNames[card.nameRes.key] ?: "",
                         isSupported = card.cardType in supportedCardTypes,
                         isKeysRequired = card.keysRequired && card.keyBundle !in loadedKeyBundles,
                         onTap = {
-                            selectedCardKey = card.nameRes.key
+                            selectedCardKey = card.uniqueKey
                         },
                     )
                 }
@@ -337,7 +337,7 @@ fun ExploreContent(
     // Bottom sheet for selected card details
     val selectedCard =
         selectedCardKey?.let { key ->
-            supportedCards.find { it.nameRes.key == key }
+            supportedCards.find { it.uniqueKey == key }
         }
     if (selectedCard != null) {
         ModalBottomSheet(

transit/src/commonMain/kotlin/com/codebutler/farebot/transit/CardInfo.kt

@@ -41,4 +41,6 @@ data class CardInfo(
     /** Brand color as 0xRRGGBB (no alpha). Null if unknown — UI will use a theme-appropriate fallback. */
     val brandColor: Int?,
     val credits: List<String> = emptyList(),
-)
+) {
+    val uniqueKey: String get() = "${nameRes.key}:${cardType.name}"
+}