fix: 去除LLM直接生成图片占位符逻辑

api/tests/test_memoir_image_parser.py

@@ -3,6 +3,8 @@ import unittest
 from app.features.memoir.memoir_images.parser import (
     build_initial_image_assets,
     parse_image_placeholders,
+    parse_narrative_json,
+    parse_narrative_to_sections,
 )
 
 
@@ -52,3 +54,25 @@ class MemoirImageParserTest(unittest.TestCase):
         self.assertEqual(len(items), 1)
         self.assertEqual(items[0]["placeholder"], "{{IMAGE:1938年初的上海弄堂口，冬日萧瑟}}")
         self.assertEqual(items[0]["description"], "1938年初的上海弄堂口，冬日萧瑟")
+
+    def test_parse_narrative_json_returns_sections_with_content_and_placeholder_info(self):
+        raw = '{"paragraphs": [{"content": "那年春天。", "image_description": "南方小镇的青石板路"}, {"content": "奶奶坐在藤椅上。", "image_description": "奶奶的藤椅"}]}'
+        segments = parse_narrative_json(raw)
+        self.assertEqual(len(segments), 2)
+        self.assertEqual(segments[0]["content"], "那年春天。")
+        self.assertEqual(segments[0]["placeholder_info"]["description"], "南方小镇的青石板路")
+        self.assertEqual(segments[1]["content"], "奶奶坐在藤椅上。")
+        self.assertEqual(segments[1]["placeholder_info"]["description"], "奶奶的藤椅")
+
+    def test_parse_narrative_to_sections_prefers_json_then_fallback_to_placeholder(self):
+        json_raw = '{"paragraphs": [{"content": "段落一", "image_description": "图一"}]}'
+        segments = parse_narrative_to_sections(json_raw)
+        self.assertEqual(len(segments), 1)
+        self.assertEqual(segments[0]["content"], "段落一")
+        self.assertEqual(segments[0]["placeholder_info"]["description"], "图一")
+
+        placeholder_raw = "正文。\n\n{{{{IMAGE:描述}}}}\n\n结尾。"
+        segments2 = parse_narrative_to_sections(placeholder_raw)
+        self.assertEqual(len(segments2), 2)
+        self.assertIn("正文", segments2[0]["content"])
+        self.assertEqual(segments2[0]["placeholder_info"]["description"], "描述")