fix(viral-video): pre_trusted_images to_domain 兼容脏数据

list() 对字符串逐字符拆分导致 pre_trusted_images 被读成 ['n','u','l','l']。
修复：
1. str 类型 → json.loads 解析为 list
2. list 类型 → 过滤长度≤5的短字符串元素（过滤字符拆分脏数据）
3. None/解析失败 → 返回 None

同时 _to_response 和 schema 已在 #2178 补 pre_trusted_images 字段。

Ref: #2175

packages/adapters/sqlalchemy_impl/viral_video_repository.py

@@ -12,16 +12,26 @@ from packages.domain.viral_video import ViralVideoJob, ViralVideoStatus
 
 
 def _to_domain(model: ViralVideoJobModel) -> ViralVideoJob:
-    """ORM → 领域实体。"""
+    """ORM → 领域实体。pre_trusted_images 兼容脏数据：双序列化字符串/字符数组/list[str]。"""
+    import json as _pti_json
+    _raw_pti = getattr(model, "pre_trusted_images", None)
+    _pti: list[str] | None = None
+    if _raw_pti is not None:
+        if isinstance(_raw_pti, str):
+            try:
+                _p = _pti_json.loads(_raw_pti)
+                if isinstance(_p, list):
+                    _pti = [u for u in _p if isinstance(u, str) and u] or None
+            except Exception:
+                _pti = None
+        elif isinstance(_raw_pti, list):
+            _f = [u for u in _raw_pti if isinstance(u, str) and len(u) > 5]
+            _pti = _f if _f else None
     return ViralVideoJob(
         id=model.id,
         user_id=model.user_id,
         images=list(model.images or []),
-        pre_trusted_images=(
-            list(getattr(model, "pre_trusted_images", None) or [])
-            if getattr(model, "pre_trusted_images", None) is not None
-            else None
-        ),
+        pre_trusted_images=_pti,
         industry=model.industry or "",
         target_customer=model.target_customer or "",
         persona_id=model.persona_id or "",