- Shrink the roster from 200 to 60 systems and drop spiral arms / core bulge for a uniform-in-area sparse disk (data/galaxy.json)
- Turn the jump network into a pure spanning tree (shortcuts off): exactly one route between any two systems, barren systems become single-gate dead-end leaves
- Remove the rendered Star entity; non-home system centers are now empty space with the star kept only as invisible dossier flavor
- Gate anchors restricted to planets (stations no longer anchor) and every non-barren system guaranteed ≥1 planet so a buildable world always exists
- Give barren dead ends 1–2 asteroid clusters drifting inside their gate's level-1 tether as the stop's only payload
- Bump save format to 2 and reject legacy format-1 saves with a clear toast message
- Update tests, docs, and README to reflect the maze layout, leaf dead ends, empty centers, and new barren cluster rules
