test(console): cover the first-run wizard's CA reconfirm path #193

What happened

The first-run wizard's "this CA is already registered, confirm its fingerprint" branch (apps/console/src/components/first-run/ca-step.tsx) has no test. The wizard's tests only exercise a fresh registration, so a regression in the reconfirm path (for example accepting a mismatched fingerprint, or never letting the operator continue) would not be caught. Noticed while restyling the wizard in #192, which kept the logic unchanged.

Expected behavior

Tests cover the reconfirm path through the public component: the already-registered state shows the fingerprint to confirm; confirming the right one continues; a mismatch or a cancel does not register anything and says why.

Environment

cryptos-web main after #192.