fix(snapshot): Lowercase sidecar filenames to match Paparazzi images

Paparazzi's `Snapshot.toFileName()` applies `.lowercase(Locale.US)` to
the snapshot name when generating image filenames. The sidecar JSON
filenames must match, so re-add the lowercase call that was removed in
e460156.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: runningcode

plugin-build/src/main/kotlin/io/sentry/android/gradle/snapshot/GenerateSnapshotTestsTask.kt

@@ -109,6 +109,7 @@ import app.cash.paparazzi.detectEnvironment
 import com.android.ide.common.rendering.api.SessionParams
 import com.android.resources.*
 import java.io.File
+import java.util.Locale
 import kotlin.math.ceil
 import org.junit.Rule
 import org.junit.Test
@@ -365,7 +366,7 @@ class $CLASS_NAME(
             else "\"" + k + "\": " + v
         }
         val sidecarName = "Paparazzi_Preview_Test_" +
-            screenshotId.replace("\\s".toRegex(), "_")
+            screenshotId.lowercase(Locale.US).replace("\\s".toRegex(), "_")
         File(imagesDir, "${'$'}{sidecarName}.json").writeText(json)
     }
 

plugin-build/src/test/kotlin/io/sentry/android/gradle/snapshot/GenerateSnapshotTestsTaskTest.kt

@@ -116,11 +116,12 @@ class GenerateSnapshotTestsTaskTest {
   }
 
   @Test
-  fun `generated sidecar filename preserves original case`() {
+  fun `generated sidecar filename is lowercased to match Paparazzi image filenames`() {
     val content = generateAndRead(packageTrees = listOf("com.example"))
 
-    assertTrue(content.contains("screenshotId.replace(\"\\\\s\".toRegex(), \"_\")"))
-    assertFalse(content.contains("lowercase"))
+    assertTrue(
+      content.contains("screenshotId.lowercase(Locale.US).replace(\"\\\\s\".toRegex(), \"_\")")
+    )
   }
 
   private fun generateAndRead(