-- Outbound message queue: the real effect of the gated email.send tool.
-- Rows land here ONLY after human approval (§15); the delivery transport
-- (SMTP / Slack / etc.) drains the queue in P4.

CREATE TABLE outbox (
    id           UUID PRIMARY KEY,
    workspace_id UUID NOT NULL REFERENCES workspaces (id),
    agent_id     UUID NOT NULL REFERENCES agents (id),
    recipient    TEXT NOT NULL,
    subject      TEXT NOT NULL,
    body         TEXT NOT NULL,
    status       TEXT NOT NULL DEFAULT 'queued' CHECK (status IN ('queued', 'sent', 'failed')),
    created_at   TIMESTAMPTZ NOT NULL DEFAULT now()
);
CREATE INDEX outbox_workspace_idx ON outbox (workspace_id, created_at DESC);