Recall-failure telemetry isolation and Bun SDK testing

Trap: clearing cloned Sentry scopes looks detached, but inherited SDK processing metadata and trace/request state can still reach the envelope. Fix: capture Recall continuation failed through brand-new current/isolation scopes, pin them as captured scopes, then reconstruct the event in beforeSend and the transport to only fixed warning metadata and one runtime-allowlisted category. Report at most once after an attempted continuation, including post-delivery failures; never report aborts or let telemetry affect the response. Verify with a real initialized SDK envelope seeded with private request/trace state and fail-first evidence against the broken revision.