Fix NPE in ImageService when contentId of Image entity is null

app/src/main/kotlin/org/gameyfin/app/games/GameService.kt

@@ -105,7 +105,7 @@ class GameService(
                 imageService.downloadIfNew(it)
             }
         } catch (e: Exception) {
-            log.error { "Error downloading images for game: ${e.message}" }
+            log.error { "Error downloading images for game '${game.title}' (${game.id}): ${e.message}" }
             log.debug(e) {}
             null
         }

app/src/main/kotlin/org/gameyfin/app/libraries/LibraryScanService.kt

@@ -376,7 +376,7 @@ class LibraryScanService(
 
                     game
                 } catch (e: Exception) {
-                    log.error { "Error downloading images for game: ${e.message}" }
+                    log.error { "Error downloading images for game '${game.title}' (${game.id}): ${e.message}" }
                     log.debug(e) {}
                     null
                 } finally {

app/src/main/kotlin/org/gameyfin/app/media/ImageService.kt

@@ -1,10 +1,10 @@
 package org.gameyfin.app.media
 
+import org.apache.tika.Tika
+import org.apache.tika.io.TikaInputStream
 import org.gameyfin.app.games.entities.Image
 import org.gameyfin.app.games.entities.ImageType
 import org.gameyfin.app.games.repositories.ImageContentStore
-import org.apache.tika.Tika
-import org.apache.tika.io.TikaInputStream
 import org.gameyfin.app.games.repositories.ImageRepository
 import org.springframework.data.repository.findByIdOrNull
 import org.springframework.stereotype.Service
@@ -22,8 +22,10 @@ class ImageService(
     fun downloadIfNew(image: Image) {
         if (image.originalUrl == null) throw IllegalArgumentException("Image must have an original URL")
 
-        imageRepository.findByOriginalUrl(image.originalUrl)?.let {
-            imageContentStore.associate(image, it.contentId)
+        val existingImage = imageRepository.findByOriginalUrl(image.originalUrl)
+
+        if (existingImage != null && existingImage.contentId != null) {
+            imageContentStore.associate(image, existingImage.contentId)
             return
         }