implement AddCategoryDialog and add a dropdown menu for adding vocabulary or categories in LibraryScreen

app/src/main/java/eu/gaudian/translator/view/library/LibraryScreen.kt

@@ -60,9 +60,12 @@ import androidx.navigation.NavHostController
 import eu.gaudian.translator.R
 import eu.gaudian.translator.model.VocabularyStage
 import eu.gaudian.translator.utils.findActivity
+import eu.gaudian.translator.view.composable.AppDropDownMenu
 import eu.gaudian.translator.view.composable.AppIcons
 import eu.gaudian.translator.view.composable.AppSwitch
+import eu.gaudian.translator.view.composable.LargeDropdownMenuItem
 import eu.gaudian.translator.view.composable.MultipleLanguageDropdown
+import eu.gaudian.translator.view.dialogs.AddCategoryDialog
 import eu.gaudian.translator.view.dialogs.CategorySelectionDialog
 import eu.gaudian.translator.view.dialogs.StageSelectionDialog
 import eu.gaudian.translator.viewmodel.CategoryViewModel
@@ -106,6 +109,8 @@ fun LibraryScreen(
 
     var showCategoryDialog by remember { mutableStateOf(false) }
     var showStageDialog by remember { mutableStateOf(false) }
+    var showAddMenu by remember { mutableStateOf(false) }
+    var showAddCategoryDialog by remember { mutableStateOf(false) }
     
     var isCategoriesView by remember { mutableStateOf(false) }
 
@@ -164,7 +169,7 @@ fun LibraryScreen(
             modifier = Modifier
                 .widthIn(max = 700.dp)
                 .fillMaxSize()
-                .padding(horizontal = 24.dp),
+                .padding(horizontal = 16.dp),
         ) {
             AnimatedVisibility(
                 visible = isHeaderVisible,
@@ -193,7 +198,7 @@ fun LibraryScreen(
                         )
                     } else {
                         LibraryTopBar(
-                            onAddClick = { /* TODO: Add new card/category */ }
+                            onAddClick = { showAddMenu = true }
                         )
                     }
 
@@ -323,6 +328,36 @@ fun LibraryScreen(
         )
     }
 
+    if (showAddMenu) {
+        AppDropDownMenu(
+            expanded = showAddMenu,
+            onDismissRequest = { showAddMenu = false }
+        ) {
+            LargeDropdownMenuItem(
+                text = stringResource(R.string.label_add_vocabulary),
+                selected = false,
+                enabled = true,
+                onClick = {
+                    showAddMenu = false
+                    navController.navigate("new_word")
+                }
+            )
+            LargeDropdownMenuItem(
+                text = stringResource(R.string.label_add_category),
+                selected = false,
+                enabled = true,
+                onClick = {
+                    showAddMenu = false
+                    showAddCategoryDialog = true
+                }
+            )
+        }
+    }
+
+    if (showAddCategoryDialog) {
+        AddCategoryDialog(onDismiss = { showAddCategoryDialog = false })
+    }
+
     if (showStageDialog) {
         val selectedItems = vocabularyItems.filter { selection.contains(it.id.toLong()) }
         StageSelectionDialog(