feat(prompts): add round-0 + zaya_v1 aggregation templates with versioned registry

tests/test_prompts.py

@@ -0,0 +1,50 @@
+import pytest
+from markovian_rsa_mlx.prompts import (
+    build_round_0_messages,
+    build_aggregation_user_content,
+    AGGREGATION_TEMPLATES,
+)
+
+
+def test_round_0_returns_chat_messages_with_user_role():
+    msgs = build_round_0_messages("What is 2+2?")
+    assert msgs == [{"role": "user", "content": "What is 2+2?"}]
+
+
+def test_zaya_v1_aggregation_includes_problem_and_K_tails():
+    body = build_aggregation_user_content(
+        original_prompt="What is 2+2?",
+        tails=["...solution attempt 1...", "...solution attempt 2..."],
+        template="zaya_v1",
+    )
+    assert "Original problem" in body
+    assert "What is 2+2?" in body
+    assert "[Approach 1]" in body
+    assert "...solution attempt 1..." in body
+    assert "[Approach 2]" in body
+    assert "...solution attempt 2..." in body
+    assert "synthesize" in body.lower()
+    assert "{K}" not in body  # placeholder must be filled
+
+
+def test_zaya_v1_uses_K_equal_len_tails():
+    body = build_aggregation_user_content(
+        original_prompt="P",
+        tails=["t1", "t2", "t3"],
+        template="zaya_v1",
+    )
+    assert "3 candidate" in body  # K=3
+    assert "[Approach 3]" in body
+
+
+def test_unknown_template_raises():
+    with pytest.raises(ValueError, match="unknown template"):
+        build_aggregation_user_content(
+            original_prompt="P",
+            tails=["t"],
+            template="does_not_exist",
+        )
+
+
+def test_aggregation_templates_registry():
+    assert "zaya_v1" in AGGREGATION_TEMPLATES