Wizard steps rendered bare .form-group divs, so CIBG's
".form-horizontal fieldset { background:#f1f5f9; margin-bottom:1.25em }"
never matched and inputs showed on white instead of the grey CIBG surface.
Wrap each logical field group per step in a <fieldset> (intake, herregistratie
and registratie wizards); CIBG then gives every group its grey surface with a
1.25em gap between groups. The shell stays group-agnostic (no outer fieldset,
which would hide the white gaps). address-fields already used a <fieldset>.
Adds intake-wizard.component.spec.ts asserting the buitenland step renders its
groups as separate fieldsets (guards against the wrapping being dropped again).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
