Sprint goal: close Phase 3 Atlas (unified nav chain, brand corps, content refinement) and establish Phase 4 foundations (bookmark system, location-culture resolution, character creation skeleton). 15 tickets assigned across server (7), client (5), copy (3). Briefings written for all four teams. DB backup updated. Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>