feat:自动剥离大模型返回的markdown代码围栏

backend/app/schemas.py

@@ -30,6 +30,13 @@ class HTMLGenerateRequest(BaseModel):
         ge=1,
         description="Optional retention days for the file.",
     )
+    preserve_markdown_fence: bool = Field(
+        default=False,
+        description=(
+            "When true, keeps outer Markdown code fences instead of stripping them "
+            "from the HTML payload."
+        ),
+    )
 
     @root_validator(pre=True)
     def normalize_aliases(cls, values: dict) -> dict:
@@ -73,6 +80,17 @@ class HTMLGenerateRequest(BaseModel):
         normalized = value.strip()
         return normalized or None
 
+    @validator("preserve_markdown_fence", pre=True)
+    def normalize_preserve_markdown_fence(cls, value: bool | str | None) -> bool:
+        if isinstance(value, bool):
+            return value
+        if value is None:
+            return False
+        if isinstance(value, str):
+            return value.strip().lower() in {"1", "true", "yes", "on"}
+
+        return bool(value)
+
     @validator("ttl_days")
     def validate_ttl_days(cls, value: int | None) -> int | None:
         if value is None: