Initial project scaffold

Full-stack homeschool web app with FastAPI backend, Vue 3 frontend,
MySQL database, and Docker Compose orchestration. Includes JWT auth,
WebSocket real-time TV dashboard, schedule builder, activity logging,
and multi-child support.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/models/base.py

@@ -0,0 +1,14 @@
+from datetime import datetime
+from sqlalchemy import func
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+class TimestampMixin:
+    created_at: Mapped[datetime] = mapped_column(default=func.now(), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        default=func.now(), server_default=func.now(), onupdate=func.now()
+    )