The toy example keeps its boundary narrow.
What this toy model checks
The trust boundary parses one Set-Cookie response, parses one later request, and checks that the returned label matches.
recompute cookie round trip
Honesty boundary
NOTE: toy HTTP cookie round trip only; not login, authentication, sessions, tracking, privacy law, SameSite, Secure, HttpOnly, expiration, domain matching, multiple cookies, storage policy, browser behavior details, CSRF, or production security config.
toy cookie label only
No client compute
The page shows already validated rows. It does not store cookies or run browser behavior.
static validated rows
Summary
A Set-Cookie response header can become a Cookie request header later.
header returns later