Refactor: Clean up unused code and fix warnings

This commit addresses several linter warnings and removes unused code to improve maintainability.

- Removed unused function  and property  in .
- Removed unused parameter  from , , and .
- Fixed a variable shadowing issue with  in .
- Inlined a redundant variable in .

app/src/main/java/de/lxtools/noteshop/MainActivity.kt

@@ -125,11 +125,7 @@ class BiometricAuthenticator(private val context: Context) {
 
     private lateinit var promptInfo: BiometricPrompt.PromptInfo
 
-    private val biometricManager = BiometricManager.from(context)
 
-    fun isBiometricAuthAvailable(): Boolean {
-        return biometricManager.canAuthenticate(BiometricManager.Authenticators.BIOMETRIC_STRONG or BiometricManager.Authenticators.DEVICE_CREDENTIAL) == BiometricManager.BIOMETRIC_SUCCESS
-    }
 
     fun promptBiometricAuth(
         title: String,

app/src/main/java/de/lxtools/noteshop/ui/AppShell.kt

@@ -204,47 +204,7 @@ fun AppShell(
         setShowPasswordDialog(true)
     }
 
-    val onRemoveEncryption: () -> Unit = {
-        val activity = context.findActivity() as FragmentActivity
-        val cipher = keyManager.getDecryptionCipher()
-        if (cipher == null) {
-            // This can happen if no key is set. In this case, just disable the feature.
-            setHasEncryptionPassword(false)
-            setIsEncryptionEnabled(false)
-            sharedPrefs.edit {
-                putBoolean("encryption_enabled", false)
-                remove("biometric_unlock_enabled")
-            }
-        }
-        val crypto = androidx.biometric.BiometricPrompt.CryptoObject(cipher!!)
 
-        biometricAuthenticator.promptBiometricAuth(
-            title = context.getString(R.string.remove_encryption),
-            subtitle = context.getString(R.string.confirm_to_remove_encryption),
-            fragmentActivity = activity,
-            crypto = crypto,
-            onSuccess = { result ->
-                result.cryptoObject?.cipher?.let { authenticatedCipher ->
-                    scope.launch {
-                        keyManager.getSecretKeyFromAuthenticatedCipher(authenticatedCipher)
-                        // Decrypt all items in all ViewModels
-                        // Decryption of individual items is no longer needed.
-
-                        // Now it's safe to delete the key
-                        keyManager.deleteKey()
-                        setHasEncryptionPassword(false)
-                        setIsEncryptionEnabled(false)
-                        sharedPrefs.edit {
-                            putBoolean("encryption_enabled", false)
-                            remove("biometric_unlock_enabled")
-                        }
-                    }
-                }
-            },
-            onFailed = {},
-            onError = { _, _ -> }
-        )
-    }
 
     val performAutomaticExport: suspend (Context, SecretKey?) -> Unit =
         remember(notesViewModel, shoppingListsViewModel, recipesViewModel, syncFolderUri) {
@@ -1096,7 +1056,7 @@ fun AppShell(
                 isEncryptionEnabled = isEncryptionEnabled,
                 onEncryptionToggle = onEncryptionToggle,
                 onSetEncryptionPassword = onSetEncryptionPassword,
-                onRemoveEncryption = onRemoveEncryption,
+
                 hasEncryptionPassword = hasEncryptionPassword,
                 biometricAuthenticator = biometricAuthenticator,
                 sharedPrefs = sharedPrefs,

app/src/main/java/de/lxtools/noteshop/ui/SettingsScreen.kt

@@ -34,7 +34,6 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.lxtools.noteshop.R
 import androidx.compose.ui.platform.LocalContext
-import androidx.biometric.BiometricManager
 import androidx.compose.ui.draw.alpha
 import de.lxtools.noteshop.ui.theme.*
 import androidx.compose.foundation.lazy.LazyRow
@@ -64,7 +63,7 @@ fun SettingsScreen(
     isEncryptionEnabled: Boolean,
     onEncryptionToggle: (Boolean) -> Unit,
     onSetEncryptionPassword: () -> Unit,
-    onRemoveEncryption: () -> Unit,
+
     hasEncryptionPassword: Boolean,
     biometricAuthenticator: BiometricAuthenticator,
     sharedPrefs: SharedPreferences,
@@ -85,10 +84,7 @@ fun SettingsScreen(
     val currentStartScreenName = startScreenOptions[currentStartScreen] ?: stringResource(R.string.start_screen_last)
     var isBiometricUnlockEnabled by remember { mutableStateOf(sharedPrefs.getBoolean("biometric_unlock_enabled", false)) }
     val context = LocalContext.current
-    val biometricManager = BiometricManager.from(context)
-    val canUseBiometrics = remember {
-        biometricManager.canAuthenticate(BiometricManager.Authenticators.BIOMETRIC_STRONG) == BiometricManager.BIOMETRIC_SUCCESS
-    }
+
     val listState = rememberLazyListState()
 
     val authenticateAndProceed: ((() -> Unit) -> Unit) = { successAction ->
@@ -289,9 +285,8 @@ fun SettingsScreen(
                             Switch(
                                 checked = isBiometricUnlockEnabled,
                                 onCheckedChange = {
-                                    val newValue = it
-                                    sharedPrefs.edit { putBoolean("biometric_unlock_enabled", newValue) }
-                                    isBiometricUnlockEnabled = newValue
+                                    sharedPrefs.edit { putBoolean ("biometric_unlock_enabled", it) }
+                                    isBiometricUnlockEnabled = it
                                 }
                             )
                         }

app/src/main/java/de/lxtools/noteshop/ui/appshell/AppContent.kt

@@ -54,7 +54,7 @@ fun AppContent(
     isEncryptionEnabled: Boolean,
     onEncryptionToggle: (Boolean) -> Unit,
     onSetEncryptionPassword: () -> Unit,
-    onRemoveEncryption: () -> Unit,
+
     hasEncryptionPassword: Boolean,
     biometricAuthenticator: BiometricAuthenticator,
     sharedPrefs: android.content.SharedPreferences,
@@ -186,7 +186,7 @@ fun AppContent(
                     isEncryptionEnabled = isEncryptionEnabled,
                     onEncryptionToggle = onEncryptionToggle,
                     onSetEncryptionPassword = onSetEncryptionPassword,
-                    onRemoveEncryption = onRemoveEncryption,
+
                     hasEncryptionPassword = hasEncryptionPassword,
                     biometricAuthenticator = biometricAuthenticator,
                     sharedPrefs = sharedPrefs,