feat: water hardness mode with sodium citrate recommendation via Codex

test_setup.py

@@ -1,23 +1,31 @@
-# Test 1: chemistry engine
-from chemistry import calculate_lye, score_recipe, find_substitutes
-
-recipe = {"coconut oil": 150, "olive oil": 350}
-result = calculate_lye(recipe, superfat=5)
-print(f"✅ Chemistry engine: NaOH = {result['naoh_g']}g")
-
-# Test 2: Ollama
-import ollama
-response = ollama.chat(
-    model="llama3.2:latest",
-    messages=[{"role": "user", "content": "Say hello in one sentence."}]
-)
-print(f"✅ Ollama: {response['message']['content']}")
-
-# Test 3: HF login
-from huggingface_hub import whoami
-user = whoami()
-print(f"✅ HF logged in as: {user['name']}")
-≈
+
+import pytest
+from chemistry import calculate_lye
+
+
+def test_chemistry_engine():
+    recipe = {"coconut oil": 150, "olive oil": 350}
+    result = calculate_lye(recipe, superfat=5)
+    assert isinstance(result, dict)
+    assert 'naoh_g' in result
+
+
+def test_ollama_optional():
+    pytest.importorskip("ollama")
+    import ollama
+    response = ollama.chat(
+        model="llama3.2:latest",
+        messages=[{"role": "user", "content": "Say hello in one sentence."}]
+    )
+    assert 'message' in response
+
+
+def test_hf_login_optional():
+    pytest.importorskip("huggingface_hub")
+    from huggingface_hub import whoami
+    user = whoami()
+    assert 'name' in user
+