added backends, improved templating, rbac

server/app/security/time.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+
+def utc_now() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+def ensure_aware_utc(value: datetime | None) -> datetime | None:
+    """Return a timezone-aware UTC datetime.
+
+    SQLite and some DB drivers may return naive datetimes even when SQLAlchemy
+    columns are declared as DateTime(timezone=True). Treat naive values as UTC
+    so comparisons with aware `datetime.now(timezone.utc)` do not crash.
+    """
+    if value is None:
+        return None
+    if value.tzinfo is None:
+        return value.replace(tzinfo=timezone.utc)
+    return value.astimezone(timezone.utc)