- split backend API into route/service/repository boundaries across stats, owner, and pathing\n- extract shared API bootstrap and helper modules\n- reduce MapLibreMap into smaller frontend map modules with extracted builders, config, popup UI, and types\n- continue worker modularization by extracting RF terrain/tile helpers alongside RF config and loss helpers\n- add repo-local architecture, DB lifecycle, link model, pathing, frontend map, and contributing docs\n\nThis is the verified refactor checkpoint: backend and frontend builds passed, worker syntax checks passed, affected containers were rebuilt, and /healthz is OK.