add logging and database migration

app/logging_config.py

@@ -0,0 +1,24 @@
+import logging
+from pathlib import Path
+
+def setup_logging(app_env: str):
+    logger = logging.getLogger()
+    logger.setLevel(logging.INFO)
+
+    fmt = logging.Formatter("%(asctime)s [%(levelname)s] %(message)s")
+
+    # Always log to console (terminal / systemd)
+    sh = logging.StreamHandler()
+    sh.setFormatter(fmt)
+    logger.addHandler(sh)
+
+    # Dev → additional file logging
+    if app_env == "dev":
+        log_dir = Path("logs")
+        log_dir.mkdir(exist_ok=True)
+        fh = logging.FileHandler(log_dir / "app.log", encoding="utf-8")
+        fh.setFormatter(fmt)
+        logger.addHandler(fh)
+
+    return logger
+