Implement verified email registration and queued TLS delivery

db/002-platform.sql

@@ -52,6 +52,8 @@ CREATE TABLE email_outbox (
     attempts integer NOT NULL DEFAULT 0,
     available_at timestamptz NOT NULL DEFAULT now(),
     lease_until timestamptz,
+    lease_id uuid,
+    expires_at timestamptz NOT NULL,
     sent_at timestamptz,
     created_at timestamptz NOT NULL DEFAULT now()
 );