Delete the /briefwechsel route in full (page, server load, eight
components and all co-located unit tests) and its end-to-end coverage
(briefwechsel-rows.visual, briefwechsel-a11y, the bilateral-correspondence
fixture, and the stale korrespondenz spec which targeted the route's
former /korrespondenz path). The card link now deep-links into document
search, so this view has no remaining inbound references.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
975223c972