refacto: rename app into backend, to prepare for frontend dev

server/backend/core/logging.py

@@ -0,0 +1,13 @@
+import logging
+import sys
+import os
+
+def setup_logging() -> None:
+    level = os.getenv("LOG_LEVEL", "INFO").upper()
+    logging.basicConfig(
+        level=getattr(logging, level, logging.INFO),
+        format="%(asctime)s [%(levelname)s] %(name)s — %(message)s",
+        datefmt="%Y-%m-%dT%H:%M:%S",
+        stream=sys.stdout,
+        force=True,
+    )