fix: complete template coverage in training data + disclose model alias

tests/test_datagen.py

@@ -1,10 +1,17 @@
-from buddhagpt.datagen import build_messages, parse_pairs, dedupe
+from buddhagpt.datagen import build_messages, parse_pairs, dedupe, interleaved_variant
 
 def test_build_messages_varies_templates():
     sutta = {"uid": "mn21", "title": "T", "text": "x" * 900}
     prompts = {build_messages(sutta, v)[1]["content"] for v in range(6)}
     assert len(prompts) == 6  # rotating templates, not one fixed prompt
 
+def test_interleaved_variant_cycles_all_templates():
+    # Any run of >=6 calls must touch every template, not just the first one or two.
+    variants = [interleaved_variant(i) for i in range(18)]
+    assert set(variants) == {0, 1, 2, 3, 4, 5}
+    assert variants[:6] == [0, 1, 2, 3, 4, 5]
+    assert variants == variants[:6] * 3
+
 def test_parse_pairs_extracts_json_lines():
     out = '{"question": "Q1?", "answer": "A1"}\n{"question": "Q2?", "answer": "A2"}'
     assert len(parse_pairs(out, uid="mn21")) == 2