add telegram auth and reminders foundation

app/models/push.py

@@ -0,0 +1,24 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, String, Text, UniqueConstraint, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+
+
+class PushSubscription(Base):
+    __tablename__ = "push_subscriptions"
+    __table_args__ = (UniqueConstraint("user_id", "endpoint", name="uq_push_user_endpoint"),)
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    user_id: Mapped[int] = mapped_column(ForeignKey("users.id", ondelete="CASCADE"), index=True)
+    endpoint: Mapped[str] = mapped_column(Text)
+    p256dh: Mapped[str | None] = mapped_column(String(256))
+    auth: Mapped[str | None] = mapped_column(String(256))
+    user_agent: Mapped[str | None] = mapped_column(String(256))
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
+    )
+
+    user = relationship("User", back_populates="push_subscriptions")