feat: add runnable simulator foundation

tests/unit/test_logging.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+import json
+import logging
+
+from app.logging import JsonFormatter
+
+
+def test_json_formatter_emits_structured_fields() -> None:
+    record = logging.LogRecord("test", logging.INFO, __file__, 1, "hello %s", ("world",), None)
+    record.request_id = "request-1"
+
+    payload = json.loads(JsonFormatter().format(record))
+
+    assert payload["message"] == "hello world"
+    assert payload["request_id"] == "request-1"
+    assert payload["level"] == "INFO"