fix 文档管理模块 & 法规对话模块

backend/app/domain/retrieval/__init__.py

@@ -1,8 +1,8 @@
 """Initialize the app.domain.retrieval package."""
 
 from .models import RetrievalQuery, RetrievedChunk
-from .ports import EmbeddingProvider, Retriever, VectorIndex
+from .ports import EmbeddingProvider, Reranker, Retriever, VectorIndex
 # Keep package boundaries explicit so backend imports stay predictable.
 
 
-__all__ = ["RetrievalQuery", "RetrievedChunk", "EmbeddingProvider", "Retriever", "VectorIndex"]
+__all__ = ["RetrievalQuery", "RetrievedChunk", "EmbeddingProvider", "Reranker", "Retriever", "VectorIndex"]

backend/app/domain/retrieval/ports.py

@@ -10,7 +10,6 @@ from .models import RetrievalQuery, RetrievedChunk
 # Keep domain contracts explicit so adapters can swap implementations cleanly.
 
 
-
 class EmbeddingProvider(ABC):
     """Provide the Embedding Provider provider."""
     @abstractmethod
@@ -41,12 +40,35 @@ class VectorIndex(ABC):
         """Handle search for the Vector Index instance."""
         pass
 
+    @abstractmethod
+    def count_by_document(self) -> dict[str, int]:
+        """Return a mapping of doc_id -> chunk count from the vector store."""
+        pass
+
+    @abstractmethod
+    def list_document_metadata(self) -> list[dict]:
+        """Return per-document metadata rows from the vector store.
+
+        Each row contains at minimum: doc_id, doc_name, chunk_count.
+        Optional fields: regulation_type, version.
+        """
+        pass
+
     @abstractmethod
     def health(self) -> dict:
         """Handle health for the Vector Index instance."""
         pass
 
 
+class Reranker(ABC):
+    """Re-score and re-order a candidate list using a cross-encoder model."""
+
+    @abstractmethod
+    def rerank(self, query: str, chunks: list[RetrievedChunk], top_k: int) -> list[RetrievedChunk]:
+        """Return top_k chunks sorted by cross-encoder score (descending)."""
+        pass
+
+
 class Retriever(ABC):
     """Provide the Retriever retriever."""
     @abstractmethod