fix: reject invalid embedding input containers

backend/app/services/embedding.py

@@ -34,7 +34,11 @@ class EmbeddingSpec:
             or self.token_limit < 2
         ):
             raise EmbeddingError("向量维度和 token 上限无效")
-        if not self.model or not isinstance(self.query_instruction, str):
+        if (
+            not isinstance(self.model, str)
+            or not self.model
+            or not isinstance(self.query_instruction, str)
+        ):
             raise EmbeddingError("模型名称或查询指令无效")
         if self.checkpoint_format not in {"safetensors", "pytorch-weights-only"}:
             raise EmbeddingError("不支持的权重格式")
@@ -138,7 +142,7 @@ class LocalEmbeddingProvider:
             raise EmbeddingError("模型 tokenizer 上限与配置不一致")
 
     def encode(self, texts: list[str], *, query: bool = False) -> list[list[float]]:
-        if any(
+        if not isinstance(texts, list) or any(
             not isinstance(text, str) or not text.strip() or len(text) > 10_000 for text in texts
         ):
             raise EmbeddingError("每条输入须为非空文本且最多 10000 字符")