prepare fastapi root layout for server deployment

app/repositories/knowledge_repository.py

@@ -0,0 +1,34 @@
+from sqlalchemy import or_, select
+from sqlalchemy.orm import Session, selectinload
+
+from app.models.knowledge import KnowledgeChunk
+
+
+class KnowledgeRepository:
+    """知识库仓储：负责评分参考指南的轻量检索。"""
+
+    def __init__(self, db: Session) -> None:
+        self.db = db
+
+    def search_chunks(
+        self,
+        department_id: int,
+        task_type: str,
+        keywords: list[str],
+        limit: int = 5,
+    ) -> list[KnowledgeChunk]:
+        """知识检索：按科室、任务类型和关键词检索知识片段。"""
+        stmt = (
+            select(KnowledgeChunk)
+            .options(selectinload(KnowledgeChunk.document))
+            .where(KnowledgeChunk.is_active.is_(True))
+            .where(or_(KnowledgeChunk.department_id == department_id, KnowledgeChunk.department_id.is_(None)))
+            .where(or_(KnowledgeChunk.task_type == task_type, KnowledgeChunk.task_type.is_(None)))
+        )
+
+        keyword_clauses = [KnowledgeChunk.chunk_text.contains(keyword) for keyword in keywords if keyword]
+        if keyword_clauses:
+            stmt = stmt.where(or_(*keyword_clauses))
+
+        stmt = stmt.order_by(KnowledgeChunk.weight.desc(), KnowledgeChunk.id.asc()).limit(limit)
+        return list(self.db.scalars(stmt).all())