-- Phones that take alerts (oxygenhub-android#16): one per device sign-in,

-- gone with it when the token is revoked. The Cloud Messaging registration

-- token addresses the phone; alerts are sealed to its X25519 public key

-- (hex), so the push service sees only ciphertext.

CREATE TABLE push_devices (

    token_id   INTEGER PRIMARY KEY REFERENCES tokens(id) ON DELETE CASCADE,

    account_id INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,

    fcm_token  TEXT NOT NULL,

    public_key TEXT NOT NULL,

    created_ms INTEGER NOT NULL,

    updated_ms INTEGER NOT NULL

);

CREATE INDEX push_devices_by_account ON push_devices (account_id);