Issue 1: repo scaffold and project structure

backend/ten31portal/audit.py

@@ -0,0 +1,29 @@
+"""Audit log helper. Every state-changing endpoint must call record_audit."""
+
+import json
+from typing import Any
+
+from sqlmodel import Session
+
+from ten31portal.models import AuditLog
+
+
+def record_audit(
+    session: Session,
+    actor_user_id: int | None,
+    action: str,
+    object_type: str,
+    object_id: int | None = None,
+    detail: Any = None,
+) -> AuditLog:
+    """Write one audit log entry and flush it."""
+    entry = AuditLog(
+        actor_user_id=actor_user_id,
+        action=action,
+        object_type=object_type,
+        object_id=object_id,
+        detail=detail,
+    )
+    session.add(entry)
+    session.flush()
+    return entry