-- Notifications table
CREATE TABLE notifications (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    type VARCHAR(50) NOT NULL,
    title VARCHAR(255) NOT NULL,
    message TEXT,
    link VARCHAR(500),
    is_read BOOLEAN NOT NULL DEFAULT false,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_notifications_user ON notifications(user_id);
CREATE INDEX idx_notifications_unread ON notifications(user_id, is_read) WHERE is_read = false;