feat(recipes): restore Copy Recipe Syntax button in recipe modal header

- Add an icon-only copy button next to Send to ComfyUI in the header
  actions row, styled as a textless variant of the neighboring pill
  buttons
- Restore fetchAndCopyRecipeSyntax() wiring against the existing
  /api/lm/recipe/{id}/syntax endpoint (context menu action unaffected)
- Add recipes.actions.copyRecipeSyntax i18n key, reusing the existing
  per-locale translations of the identical context menu string
- Sync modal test fixtures and add copySyntax tests

locales/de.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "Send to ComfyUI",
             "sendRecipe": "Send to ComfyUI",
+            "copyRecipeSyntax": "Rezept-Syntax kopieren",
             "deleteRecipeWithShortcut": "Rezept löschen (Del)"
         },
         "navigation": {

locales/en.json

@@ -860,6 +860,7 @@
     "actions": {
       "sendCheckpoint": "Send to ComfyUI",
       "sendRecipe": "Send to ComfyUI",
+      "copyRecipeSyntax": "Copy Recipe Syntax",
       "deleteRecipeWithShortcut": "Delete recipe (Del)"
     },
     "navigation": {

locales/es.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "Enviar a ComfyUI",
             "sendRecipe": "Enviar a ComfyUI",
+            "copyRecipeSyntax": "Copiar sintaxis de receta",
             "deleteRecipeWithShortcut": "Eliminar receta (Del)"
         },
         "navigation": {

locales/fr.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "Envoyer vers ComfyUI",
             "sendRecipe": "Envoyer vers ComfyUI",
+            "copyRecipeSyntax": "Copier la syntaxe de la recipe",
             "deleteRecipeWithShortcut": "Supprimer la Recipe (Del)"
         },
         "navigation": {

locales/he.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "שלח ל-ComfyUI",
             "sendRecipe": "שלח ל-ComfyUI",
+            "copyRecipeSyntax": "העתק תחביר מתכון",
             "deleteRecipeWithShortcut": "מחק מתכון (Del)"
         },
         "navigation": {

locales/ja.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "ComfyUIへ送信",
             "sendRecipe": "ComfyUIへ送信",
+            "copyRecipeSyntax": "レシピ構文をコピー",
             "deleteRecipeWithShortcut": "レシピを削除（Del）"
         },
         "navigation": {

locales/ko.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "ComfyUI로 보내기",
             "sendRecipe": "ComfyUI로 보내기",
+            "copyRecipeSyntax": "레시피 문법 복사",
             "deleteRecipeWithShortcut": "레시피 삭제(Del)"
         },
         "navigation": {

locales/ru.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "Отправить в ComfyUI",
             "sendRecipe": "Отправить в ComfyUI",
+            "copyRecipeSyntax": "Копировать синтаксис рецепта",
             "deleteRecipeWithShortcut": "Удалить рецепт (Del)"
         },
         "navigation": {

locales/zh-CN.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "发送到 ComfyUI",
             "sendRecipe": "发送到 ComfyUI",
+            "copyRecipeSyntax": "复制配方语法",
             "deleteRecipeWithShortcut": "删除配方（Del）"
         },
         "navigation": {

locales/zh-TW.json

@@ -860,6 +860,7 @@
         "actions": {
             "sendCheckpoint": "傳送到 ComfyUI",
             "sendRecipe": "傳送到 ComfyUI",
+            "copyRecipeSyntax": "複製配方語法",
             "deleteRecipeWithShortcut": "刪除配方（Del）"
         },
         "navigation": {