Add language parameter for multi-language support

nodes.py

@@ -441,6 +441,9 @@ class WriteChapters(BatchNode):
                     next_idx = chapter_order[i+1]
                     next_chapter = chapter_filenames[next_idx]
 
+                # Get language from shared store, default to English
+                language = shared.get("language", "english")
+
                 items_to_process.append({
                     "chapter_num": i + 1,
                     "abstraction_index": abstraction_index,
@@ -451,6 +454,7 @@ class WriteChapters(BatchNode):
                     "chapter_filenames": chapter_filenames,  # Add chapter filenames mapping
                     "prev_chapter": prev_chapter,  # Add previous chapter info
                     "next_chapter": next_chapter,  # Add next chapter info
+                    "language": language,  # Add language for multi-language support
                     # previous_chapters_summary will be added dynamically in exec
                 })
             else:
@@ -476,8 +480,16 @@ class WriteChapters(BatchNode):
         # Use the temporary instance variable
         previous_chapters_summary = "\n---\n".join(self.chapters_written_so_far)
 
+        # Get language from item, default to English
+        language = item.get("language", "english")
+
+        # Add language instruction if not English
+        language_instruction = ""
+        if language.lower() != "english":
+            language_instruction = f"Write this tutorial chapter in {language}. Ensure all explanations, examples, and comments are in {language}.\n\n"
 
         prompt = f"""
+{language_instruction}
 Write a very beginner-friendly tutorial chapter (in Markdown format) for the project `{project_name}` about the concept: "{abstraction_name}". This is Chapter {chapter_num}.
 
 Concept Details: