test: add DELETE endpoint tests and ingest integration tests

tests/test_api.py

@@ -110,3 +110,31 @@ class TestSecurity:
             json={"file_path": "C:\\Windows\\System32\\config\\SAM"},
         )
         assert response.status_code in (400, 403)
+
+
+class TestDeleteEndpoint:
+    """删除端点."""
+
+    def test_delete_nonexistent(self, client):
+        """删除不存在的文件返回 404."""
+        response = client.delete("/api/v1/documents/nonexistent.md")
+        assert response.status_code == 404
+
+    def test_delete_ingested(self, client):
+        """删除已入库文件后搜索不再返回."""
+        # 入库
+        ingest_resp = client.post(
+            "/api/v1/ingest",
+            json={"content": "# Test Delete\nHello.", "file_name": "delete-test.md"},
+        )
+        assert ingest_resp.status_code == 200, f"ingest failed: {ingest_resp.json()}"
+        # 删除
+        response = client.delete("/api/v1/documents/delete-test.md")
+        assert response.status_code == 200, f"delete failed: {response.json()}"
+        # 搜索验证已删除
+        search_resp = client.post(
+            "/api/v1/search", json={"query": "Test Delete", "top_k": 3}
+        )
+        results = search_resp.json()["results"]
+        sources = [r["source_file"] for r in results]
+        assert "delete-test.md" not in sources