CREATE TABLE push_tokens (
    token        TEXT PRIMARY KEY,
    human_id     TEXT NOT NULL REFERENCES humans(id) ON DELETE CASCADE,
    platform     TEXT NOT NULL CHECK (platform IN ('ios', 'android')),
    app_version  TEXT,
    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    last_seen_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX push_tokens_human_id_idx ON push_tokens (human_id);