Consolidates the hansPerson / annaPerson fixture into a makePerson()
factory matching the makeDoc convention, adds an assertion that
the bilateral list renders one ConversationThumbnail tile per
document (catches a broken {#each} keying wired around the
DistributionBar), and decouples the DistributionBar aria-label
assertion from the German locale now that i18n lands via Paraglide.
Refs #305
Fixes @saraholt concerns 3 + 4 from PR review
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
03616f0728