refactor(memory): require archive count in prompt

nanobot/templates/agent/consolidator_archive.md

@@ -1,10 +1,6 @@
-{% if archive_count is defined %}
 Create a memory overview for only the final {{ archive_count }} conversation messages immediately before this instruction. Earlier messages are context for resolving references; do not summarize them again.
 
 Do not call tools. Return only the overview, following these memory rules:
-{% else %}
-Extract key facts from this conversation. For each fact, annotate its memory attributes.
-{% endif %}
 
 Only SNIP facts deserve a non-[skip] mark:
 - Signal: would the user need to repeat this if forgotten?

tests/agent/test_consolidator.py

@@ -233,9 +233,10 @@ class TestConsolidatorSummarize:
 
 class TestConsolidatorPromptContract:
     def test_archive_prompt_outputs_attribute_tags_without_missing_context_claims(self):
-        prompt = render_template("agent/consolidator_archive.md", strip=True)
+        prompt = render_template("agent/consolidator_archive.md", strip=True, archive_count=4)
 
         assert "SNIP" in prompt
+        assert "final 4 conversation messages" in prompt
         for mark in ("[permanent]", "[durable]", "[ephemeral]", "[correction]", "[skip]"):
             assert mark in prompt
         assert "check context below" not in prompt.lower()