Design: lower tintAlpha (0.80/0.86) for more blob bleed-through, accent-tinted
gradient borders + level1 shadow on active items, specular borders on search bar
and user card, accent gradient avatar, separator line in context menu.
Features: live search filter, "Titel generieren" (Sparkles, manual POST with
{ manual: true }), "Duplizieren" (copies all messages with new IDs + parentId
chain), titleGenerated field on ConversationSummary/Entity (Room v4).
558b1be675