feat: add notifications_enabled toggle for users (web + Android)

android/app/src/main/java/com/devlab/app/data/model/LoginModels.kt

@@ -21,7 +21,8 @@ data class ProfileUpdateRequest(
     val email: String,
     val current_password: String? = null,
     val new_password: String? = null,
-    val confirm_password: String? = null
+    val confirm_password: String? = null,
+    val notifications_enabled: Boolean? = null
 )
 
 @Serializable
@@ -51,5 +52,6 @@ data class UserProfile(
     val username: String = "",
     val email: String = "",
     val role: String = "",
-    val created_at: String? = null
+    val created_at: String? = null,
+    val notifications_enabled: Boolean = true
 )

android/app/src/main/java/com/devlab/app/data/repository/ProfileRepository.kt

@@ -24,14 +24,16 @@ class ProfileRepository {
         email: String,
         currentPassword: String?,
         newPassword: String?,
-        confirmPassword: String?
+        confirmPassword: String?,
+        notificationsEnabled: Boolean = true
     ): Result<String> {
         return try {
             val request = ProfileUpdateRequest(
                 email = email,
                 current_password = currentPassword?.takeIf { it.isNotBlank() },
                 new_password = newPassword?.takeIf { it.isNotBlank() },
-                confirm_password = confirmPassword?.takeIf { it.isNotBlank() }
+                confirm_password = confirmPassword?.takeIf { it.isNotBlank() },
+                notifications_enabled = notificationsEnabled
             )
             val response = api.updateProfile(request)
             if (response.success) {

android/app/src/main/java/com/devlab/app/ui/profile/ProfileScreen.kt

@@ -249,6 +249,49 @@ fun ProfileScreen(
                 }
             }
 
+            Spacer(modifier = Modifier.height(16.dp))
+
+            Card(
+                modifier = Modifier.fillMaxWidth(),
+                colors = CardDefaults.cardColors(
+                    containerColor = MaterialTheme.colorScheme.surface
+                ),
+                elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
+            ) {
+                Column(modifier = Modifier.padding(16.dp)) {
+                    Text(
+                        text = "Notifications",
+                        style = MaterialTheme.typography.titleMedium,
+                        fontWeight = FontWeight.SemiBold
+                    )
+
+                    Spacer(modifier = Modifier.height(12.dp))
+
+                    Row(
+                        modifier = Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.SpaceBetween,
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        Column(modifier = Modifier.weight(1f)) {
+                            Text(
+                                text = "Push Notifications",
+                                style = MaterialTheme.typography.bodyLarge
+                            )
+                            Text(
+                                text = "Receive alerts for threshold breaches and app updates",
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
+                        }
+                        Switch(
+                            checked = state.notificationsEnabled,
+                            onCheckedChange = viewModel::updateNotificationsEnabled,
+                            enabled = !state.isSaving
+                        )
+                    }
+                }
+            }
+
             if (state.error != null) {
                 Spacer(modifier = Modifier.height(16.dp))
                 Card(

android/app/src/main/java/com/devlab/app/ui/profile/ProfileViewModel.kt

@@ -23,7 +23,8 @@ data class ProfileUiState(
     val successMessage: String? = null,
     val emailError: String? = null,
     val newPasswordError: String? = null,
-    val confirmPasswordError: String? = null
+    val confirmPasswordError: String? = null,
+    val notificationsEnabled: Boolean = true
 )
 
 class ProfileViewModel : ViewModel() {
@@ -44,7 +45,8 @@ class ProfileViewModel : ViewModel() {
                         isLoading = false,
                         username = profile.username,
                         email = profile.email,
-                        role = profile.role
+                        role = profile.role,
+                        notificationsEnabled = profile.notifications_enabled
                     )
                 },
                 onFailure = { e ->
@@ -61,6 +63,10 @@ class ProfileViewModel : ViewModel() {
         _uiState.value = _uiState.value.copy(email = value, error = null, successMessage = null, emailError = null)
     }
 
+    fun updateNotificationsEnabled(value: Boolean) {
+        _uiState.value = _uiState.value.copy(notificationsEnabled = value)
+    }
+
     fun updateCurrentPassword(value: String) {
         _uiState.value = _uiState.value.copy(currentPassword = value, error = null, successMessage = null)
     }
@@ -103,7 +109,8 @@ class ProfileViewModel : ViewModel() {
                 state.email,
                 state.currentPassword.takeIf { it.isNotBlank() },
                 state.newPassword.takeIf { it.isNotBlank() },
-                state.confirmPassword.takeIf { it.isNotBlank() }
+                state.confirmPassword.takeIf { it.isNotBlank() },
+                state.notificationsEnabled
             )
             result.fold(
                 onSuccess = { message ->