fix(init): address registry review feedback

Agent-Logs-Url: https://github.com/MemPalace/mempalace/sessions/76794fde-2383-4674-ab36-f89ad803eeb2

Co-authored-by: igorls <4753812+igorls@users.noreply.github.com>

tests/test_known_entities_registry.py

@@ -114,6 +114,13 @@ def test_dict_format_existing_category_gets_new_keys(temp_registry):
     assert data["people"]["Carol"] is None
 
 
+def test_dict_format_dedupes_case_insensitively_and_stringifies_new_names(temp_registry):
+    temp_registry.write_text(json.dumps({"people": {"Alice": "ALC"}}))
+    miner.add_to_known_entities({"people": ["alice", 123]})
+    data = json.loads(temp_registry.read_text())
+    assert data["people"] == {"Alice": "ALC", "123": None}
+
+
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