Fix memoir image prompt parsing and host allowlist

api/tests/test_memoir_image_prompting.py

@@ -62,6 +62,41 @@ class MemoirImagePromptingTest(unittest.TestCase):
         self.assertEqual(result["style"], "watercolor")
         self.assertEqual(result["size"], "1024x1024")
 
+    def test_prompt_service_parses_markdown_wrapped_json_response(self):
+        settings = MemoirImageSettings(
+            enabled=True,
+            max_per_chapter=2,
+            provider="liblib",
+            default_style="watercolor",
+            default_size="1024x1024",
+            poll_interval_seconds=3,
+            max_attempts=20,
+            liblib_template_uuid="tpl-uuid",
+        )
+        llm = Mock()
+        llm.invoke.return_value.content = """```json
+{
+  "prompt": "A middle-aged teacher stands on the empty stage, realistic, cinematic lighting",
+  "style": "realistic",
+  "size": "1280x720"
+}
+```"""
+        service = MemoirImagePromptService(llm=llm, settings=settings)
+
+        result = service.build_prompt(
+            chapter_title="二十出头 · 在小镇讲台上种下第一粒种子",
+            chapter_category="career_early",
+            description="空荡荡的教室讲台前，一个年轻老师站着",
+            context_excerpt="第一次站上讲台，心里紧张又兴奋。",
+        )
+
+        self.assertEqual(
+            result["prompt"],
+            "A middle-aged teacher stands on the empty stage, realistic, cinematic lighting",
+        )
+        self.assertEqual(result["style"], "realistic")
+        self.assertEqual(result["size"], "1280x720")
+
     @patch("api.services.memoir_images.prompting.logger")
     def test_prompt_service_logs_warning_and_falls_back_when_llm_response_is_invalid(
         self, logger_mock
@@ -89,4 +124,9 @@ class MemoirImagePromptingTest(unittest.TestCase):
 
         self.assertIn("childhood memory", result["prompt"])
         self.assertNotIn("奶奶坐在院子里的藤椅上", result["prompt"])
-        logger_mock.warning.assert_called_once()
+        logger_mock.warning.assert_called_once_with(
+            "图片 prompt 生成回退到默认模板: chapter_category=%s, title=%s, error=%s",
+            "childhood",
+            "童年的夏天",
+            unittest.mock.ANY,
+        )