Obfuscate client key field as password with visibility toggle

Add password masking to the client key field for better security. Users can toggle visibility using an eye icon button to view or hide the key as needed.

app/src/main/java/com/mattintech/simplelogupload/ui/screens/SettingsScreen.kt

@@ -11,11 +11,15 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.QrCodeScanner
+import androidx.compose.material.icons.filled.Visibility
+import androidx.compose.material.icons.filled.VisibilityOff
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.text.input.VisualTransformation
 import androidx.compose.ui.unit.dp
 import com.journeyapps.barcodescanner.ScanContract
 import com.mattintech.simplelogupload.R
@@ -54,6 +58,7 @@ fun SettingsScreen(
     var askBeforeUpload by remember {
         mutableStateOf(PreferencesUtil.getAskBeforeUpload(context))
     }
+    var clientKeyVisible by remember { mutableStateOf(false) }
 
     var serverAddressError by remember { mutableStateOf<String?>(null) }
     var serverPortError by remember { mutableStateOf<String?>(null) }
@@ -266,6 +271,15 @@ fun SettingsScreen(
                 modifier = Modifier.fillMaxWidth(),
                 isError = clientKeyError != null,
                 supportingText = clientKeyError?.let { { Text(it) } },
+                visualTransformation = if (clientKeyVisible) VisualTransformation.None else PasswordVisualTransformation(),
+                trailingIcon = {
+                    IconButton(onClick = { clientKeyVisible = !clientKeyVisible }) {
+                        Icon(
+                            imageVector = if (clientKeyVisible) Icons.Filled.Visibility else Icons.Filled.VisibilityOff,
+                            contentDescription = if (clientKeyVisible) "Hide client key" else "Show client key"
+                        )
+                    }
+                },
                 singleLine = true
             )