test(backend): update query tests for sub-question generation (sub-phase 2.3)

Update prompt assertion in decomposer test and field assertions in query endpoint tests to match extracted_questions rename.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/app/test/test_phase1_query.py

@@ -49,8 +49,8 @@ class TestQuery:
 
         assert response.status_code == 200
         data = response.json()
-        assert "keywords" in data
-        assert data["keywords"] == ["test", "keywords"]
+        assert "extracted_questions" in data
+        assert data["extracted_questions"] == ["test", "keywords"]
         assert "answer" in data
         assert "- Bullet point answer" in data["answer"]
         assert "sources" in data
@@ -84,7 +84,7 @@ class TestQuery:
 
         assert response.status_code == 200
         data = response.json()
-        assert data["keywords"] == ["test"]
+        assert data["extracted_questions"] == ["test"]
         assert "could not find" in data["answer"].lower()
         assert data["sources"] == []
 

backend/app/test/test_phase1_query_decomposer.py

@@ -25,7 +25,7 @@ async def test_decompose_valid_json():
     decomposer = QueryDecomposer(llm)
     result: List[str] = await decomposer.decompose("What are keywords for X?")
     assert result == ["alpha", "beta", "gamma"]
-    assert llm.last_prompt == "Given question: 'What are keywords for X?', extract key search keywords as JSON array"
+    assert llm.last_prompt == "Given this question: 'What are keywords for X?'\n\nBreak it down into 2-5 simplified sub-questions that would help search for relevant information. Each sub-question should be short and focused on one aspect. Return as a JSON array of strings."
 
 
 async def test_decompose_empty_question_returns_empty():