fix: support Compose previews for biometric authentication on Android

- Update `rememberBiometricPlatformWrapper` to check `LocalInspectionMode` and provide a fallback `FragmentActivity` instance during previews.
- Prevent ClassCastExceptions in Compose Preview by avoiding the cast of `LocalActivity.current` when in inspection mode.
- Update `SignInScreenPreview` to explicitly enable biometric visibility for layout verification.

Author: softartdev

app/android/src/main/java/com/softartdev/notedelight/MainPreview.kt

@@ -25,7 +25,7 @@ annotation class PreviewDeviceMode
 
 @PreviewDeviceMode
 @Composable
-fun SignInScreenPreview() = PreferableMaterialTheme { SignInScreenBody() }
+fun SignInScreenPreview() = PreferableMaterialTheme { SignInScreenBody(biometricVisible = true) }
 
 @PreviewDeviceMode
 @Composable

core/ui/src/androidMain/kotlin/com/softartdev/notedelight/ui/BiometricPlatformHelper.android.kt

@@ -3,11 +3,15 @@ package com.softartdev.notedelight.ui
 import androidx.activity.compose.LocalActivity
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.fragment.app.FragmentActivity
 import com.softartdev.notedelight.interactor.BiometricPlatformWrapper
 
 @Composable
 actual fun rememberBiometricPlatformWrapper(): BiometricPlatformWrapper {
-    val fragmentActivity = LocalActivity.current as FragmentActivity
+    val fragmentActivity: FragmentActivity = when (LocalInspectionMode.current) {
+        true -> FragmentActivity() // Create a new FragmentActivity instance for preview mode
+        false -> LocalActivity.current as FragmentActivity
+    }
     return remember(key1 = fragmentActivity) { BiometricPlatformWrapper(fragmentActivity) }
 }