feat: initialize aivideo project

backend/app/models/base.py

@@ -0,0 +1,18 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, MetaData, func
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+
+class Base(DeclarativeBase):
+    metadata = MetaData()
+
+
+class TimestampMixin:
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), nullable=False
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now(), nullable=False
+    )
+