feat(export): 批量导出后生成 AI 穿搭 Excel，每印花子目录一行 (§17.23)

添加印花批量导出完成后，自动在输出目录生成与时间戳目录同名的 xlsx
文件（docs/02 §6.12）；每个有效印花子目录一行，C 列指向该子目录路径，
AI 穿搭页直接选取即可触发目录扇出逻辑（§19.12），无需手工填写 Excel。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/services/excel_service.py

@@ -1,8 +1,8 @@
 import logging
 from pathlib import Path
-from typing import List
+from typing import List, Sequence, Tuple
 
-from openpyxl import load_workbook
+from openpyxl import Workbook, load_workbook
 
 from core.models import OutfitResult, OutfitTask
 
@@ -149,6 +149,27 @@ def read_all_rows(excel_path):
         workbook.close()
 
 
+_OUTFIT_SOURCE_HEADERS = ["标题", "货号", "衣服图路径", "生成结果图片路径", "完成状态", "失败原因"]
+
+
+def write_outfit_source_excel(excel_path, rows):
+    """Create an AI-outfit source Excel alongside a compose run directory (docs/02 §6.12).
+
+    rows: ordered sequence of (print_name, subdir_path) pairs.
+    subdir_path should end with a path separator so AI穿搭 treats it as a directory.
+    Columns: A=print_name, B=empty(货号可空), C=subdir_path, D/E/F=empty (AI穿搭 writes back).
+    """
+    rows = list(rows)
+    wb = Workbook()
+    ws = wb.active
+    ws.append(_OUTFIT_SOURCE_HEADERS)
+    for print_name, subdir_path in rows:
+        ws.append([print_name, None, subdir_path, None, None, None])
+    wb.save(str(excel_path))
+    wb.close()
+    logger.info("Wrote outfit source Excel: %s (%d rows)", excel_path, len(rows))
+
+
 def write_outfit_result(excel_path, result):
     """Write one outfit result to columns D/E/F and save immediately."""
     if not isinstance(result, OutfitResult):