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/activity.py

@@ -0,0 +1,24 @@
+from datetime import date
+from sqlalchemy import Date, ForeignKey, Integer, Text
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from app.models.base import Base, TimestampMixin
+
+
+class ActivityLog(TimestampMixin, Base):
+    __tablename__ = "activity_logs"
+
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    child_id: Mapped[int] = mapped_column(ForeignKey("children.id", ondelete="CASCADE"), nullable=False)
+    subject_id: Mapped[int | None] = mapped_column(
+        ForeignKey("subjects.id", ondelete="SET NULL"), nullable=True
+    )
+    session_id: Mapped[int | None] = mapped_column(
+        ForeignKey("daily_sessions.id", ondelete="SET NULL"), nullable=True
+    )
+    log_date: Mapped[date] = mapped_column(Date, nullable=False)
+    notes: Mapped[str | None] = mapped_column(Text, nullable=True)
+    duration_minutes: Mapped[int | None] = mapped_column(Integer, nullable=True)
+
+    child: Mapped["Child"] = relationship("Child", back_populates="activity_logs")  # noqa: F821
+    subject: Mapped["Subject | None"] = relationship("Subject", back_populates="activity_logs")  # noqa: F821
+    session: Mapped["DailySession | None"] = relationship("DailySession", back_populates="activity_logs")  # noqa: F821