feat(xcstrings): add empty translation entries for untranslated items

When an item has no localizations but should be translated, this change ensures an empty translation entry is added for each language. This helps maintain consistency in the resource map and supports workflows where untranslated items need explicit placeholders.

Author: WendellXY

langcodec/src/formats/xcstrings.rs

@@ -129,6 +129,36 @@ impl TryFrom<Format> for Vec<Resource> {
                 custom.insert("extraction_state".to_string(), extraction_state.to_string());
             }
 
+            if item.localizations.is_empty() {
+                if item.should_translate.unwrap_or(true) {
+                    // If the item is empty and should be translated, add a new entry for each language
+                    //
+                    // This method requires that all languages are already present in the resource map, in
+                    // other words, the translated items must be presented above the untranslated items.
+                    let lang_codes = resource_map.keys().cloned().collect::<Vec<_>>();
+                    for lang_code in lang_codes {
+                        resource_map
+                            .entry(lang_code.clone())
+                            .or_insert(Resource {
+                                metadata: Metadata {
+                                    language: lang_code.clone(),
+                                    domain: String::default(),
+                                    custom: custom_meta.clone(),
+                                },
+                                entries: Vec::new(),
+                            })
+                            .add_entry(Entry {
+                                id: id.clone(),
+                                value: Translation::Singular("".to_string()),
+                                comment: item.comment.clone(),
+                                status: EntryStatus::Translated,
+                                custom: custom.clone(),
+                            });
+                    }
+                }
+                continue;
+            }
+
             for (lang_code, localization) in item.localizations {
                 if let Some(translation) = localization.to_translation() {
                     let lang_code = lang_code.to_string();