feat(server): add workbench API, DSH planner worker and RAG pipeline

server/tests/test_rag_rerank.py

@@ -0,0 +1,19 @@
+import os
+
+from app.rag import rerank
+
+
+def test_rerank_disabled_is_stable(monkeypatch):
+    monkeypatch.delenv("RAG_RERANKER_MODEL", raising=False)
+    rows = [{"id": "a", "text": "第一"}, {"id": "b", "text": "第二"}]
+    assert rerank.rerank(rows, "问题") == rows
+    metric = rerank.last_metric()
+    assert metric["fallback"] is True
+    assert metric["reranked_count"] == 0
+
+
+def test_rerank_local_model_missing_falls_back(monkeypatch, tmp_path):
+    monkeypatch.setenv("RAG_RERANKER_MODEL", str(tmp_path / "missing"))
+    rows = [{"id": "a", "text": "第一"}, {"id": "b", "text": "第二"}]
+    assert rerank.rerank(rows, "问题") == rows
+    assert rerank.last_metric()["fallback"] is True