fix(navigation): dynamically update bottom navigation items

app/src/main/java/com/m57/hermescontrol/Navigation.kt

@@ -179,12 +179,11 @@ fun MainNavigation() {
     val scope = rememberCoroutineScope()
 
     // Read dynamic bottom-nav config.
-    // NB: deliberately NOT wrapped in remember { … } — AuthManager values change
-    // when the user customises items in Settings (saved to SharedPreferences).
-    // Without a key that tracks prefs changes, remember would cache the stale
-    // defaults and the NavigationBar would never reflect the user's picks.
-    // Reading fresh on every recomposition is negligible (pure map over 18 items).
-    val bottomNavItems = resolveBottomNavItems(AuthManager.getBottomNavItems())
+    // AuthManager.bottomNavItemsFlow is a StateFlow that emits updates when the user
+    // customises items in Settings. Using collectAsState() ensures the NavigationBar
+    // recomposes and reflects choices instantly.
+    val bottomNavItemsState by AuthManager.bottomNavItemsFlow.collectAsState()
+    val bottomNavItems = resolveBottomNavItems(bottomNavItemsState)
     val bottomNavKeys = remember(bottomNavItems) { bottomNavItems.map { it.key }.toSet() }
 
     // Sync primary screens to NavigationController

app/src/main/java/com/m57/hermescontrol/data/local/AuthManager.kt

@@ -5,6 +5,9 @@ import android.content.SharedPreferences
 import androidx.security.crypto.EncryptedSharedPreferences
 import androidx.security.crypto.MasterKey
 import com.m57.hermescontrol.theme.ThemePreference
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 
 /**
  * Singleton that manages encrypted storage of the Hermes dashboard token
@@ -29,6 +32,9 @@ object AuthManager {
     @Volatile
     private var prefs: SharedPreferences? = null
 
+    private val _bottomNavItemsFlow = MutableStateFlow<List<String>>(emptyList())
+    val bottomNavItemsFlow: StateFlow<List<String>> = _bottomNavItemsFlow.asStateFlow()
+
     /**
      * Initialise the encrypted preferences.
      * Call this once from Application.onCreate() or MainActivity.onCreate().
@@ -51,6 +57,8 @@ object AuthManager {
                     EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
                     EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM,
                 )
+            
+            _bottomNavItemsFlow.value = getBottomNavItems()
         }
     }
 
@@ -134,5 +142,6 @@ object AuthManager {
     /** Persist the ordered list of bottom-nav item keys (max 5, data-object names). */
     fun setBottomNavItems(items: List<String>) {
         requirePrefs().edit().putString(KEY_BOTTOM_NAV_ITEMS, items.joinToString(",")).apply()
+        _bottomNavItemsFlow.value = items
     }
 }