address PR review feedback

merge duplicate prompt tests into one, fix misplaced docstring, loosen
brittle double-space assertion to just check location line content,
add docstring to test_model_config_values explaining why values are pinned

Author: apkostka

backend/tests/test_constants.py

@@ -106,7 +106,12 @@ def test_vertex_ai_datastore_uri_extraction(self, mock_path):
 
 
 def test_model_config_values():
-    """Verify hard-coded model config values are sensible."""
+    """Pin model config values that affect legal advice quality.
+
+    Low temperature and top_p produce consistent, citation-heavy responses
+    rather than creative ones. Changing these accidentally could degrade the
+    quality of legal guidance, so this test should break loudly.
+    """
     from tenantfirstaid.constants import SINGLETON
 
     assert SINGLETON.MODEL_TEMPERATURE == 0.1

backend/tests/test_langchain_chat_manager.py

@@ -10,25 +10,13 @@
 from tenantfirstaid.location import UsaState
 
 
-def test_system_prompt_includes_location(oregon_state, portland_city):
-    state = oregon_state
-    city = portland_city
-
-    chat_manager = LangChainChatManager()
-
+def test_system_prompt_includes_city_and_state(oregon_state, portland_city):
     """Test that system prompt includes user location."""
-    prompt = chat_manager._prepare_system_prompt(city, state)
-
-    assert "Portland OR" in prompt
-
-
-def test_prepare_system_prompt_includes_city_state(oregon_state, portland_city):
-    state = oregon_state
-    city = portland_city
     chat_manager = LangChainChatManager()
+    prompt = chat_manager._prepare_system_prompt(portland_city, oregon_state)
 
-    instructions = chat_manager._prepare_system_prompt(city, state)
-    assert f"The user is in {city.capitalize()} {state.upper()}." in instructions
+    assert "Portland" in prompt
+    assert "OR" in prompt
 
 
 def test_tools_include_rag_retrieval():
@@ -43,11 +31,11 @@ def test_tools_include_rag_retrieval():
 
 
 def test_system_prompt_no_city(oregon_state):
+    """When no city is provided, the location line should mention state only."""
     chat_manager = LangChainChatManager()
     prompt = chat_manager._prepare_system_prompt(None, oregon_state)
+    assert "The user is in" in prompt
     assert "OR" in prompt
-    # City portion should be empty.
-    assert "The user is in  OR." in prompt
 
 
 def test_system_prompt_state_only():