Server Action alert noise reduced

Transient Server Action failures no longer flood error tracking; real issues are easier to spot.

Bug Fixes

Server Action requests sometimes fail with transient network issues—a 502 from a deploy rotation, connection resets, timeouts. These aren't application faults, but Next's error handler logs them generically as "unexpected response," drowning out actual errors in Sentry. We now suppress these benign failures from error tracking when they originate from the Server Action module, while preserving alerts for genuine unexpected responses elsewhere in your app.