feat: opener shows sex only with age or nationality

nodes.py

@@ -304,12 +304,15 @@ def build_description(sex, nat, age, skin_texture,
         if s:
             parts.append(fmt.format(s))
 
-    # Opener: "34 year old Brazilian female"
+    # Opener: "34 year old Brazilian female". Sex is shown only alongside an age
+    # or nationality, so a face-only fragment does not start with a bare "female".
     age_str = f"{age['age']} year old" if age else None
     nat_str = nat_text(nat) or None
     sex_str = sex if sex else None
-    opener_parts = [p for p in [age_str, nat_str, sex_str] if p]
+    opener_parts = [p for p in [age_str, nat_str] if p]
     if opener_parts:
+        if sex_str:
+            opener_parts.append(sex_str)
         parts.append(" ".join(opener_parts))
 
     add(face_shape, "{} face")

test_random_person.py

@@ -153,6 +153,21 @@ class TestBuildDescription(unittest.TestCase):
         s = core.build_description(*args)
         self.assertNotIn("eyes eyes", s)
 
+    def test_opener_omits_bare_sex(self):
+        # sex present but no age and no nationality -> no leading "female".
+        args = [""] + [None] * 17
+        args[0] = "female"                 # sex positional slot
+        args[4] = {"description": "oval"}  # face_shape slot -> "oval face"
+        s = core.build_description(*args)
+        self.assertTrue(s.startswith("oval face"), s)
+        self.assertNotIn("female", s)
+
+    def test_opener_keeps_sex_with_age(self):
+        # age + sex -> "<n> year old female ..."
+        s = core.build_description(
+            "female", None, {"age": 30}, *( [None] * 15 ))
+        self.assertIn("year old female", s)
+
 
 class TestBodyData(unittest.TestCase):