- Replace the annular-band scatter (minOrbit/maxOrbit/minEdgeGap) with a ring-based placement: objects sit on one or two orbits around the home world, governed by center-to-center `minSpacing` and `maxNeighbor`
- Free-space stations (deep-space stations, waypoints) are now layout objects alongside planets; planet-bound settlements stay features of their planet
- Handle the N=11 case (9 planets + 2 stations) with an inner 3-ring + outer 8-ring; chain outward defensively for any larger N
- Update tests to verify the new spacing invariants, the two-orbit case, and determinism including station positions
- Refresh PROJECT_NOTES and the data-file comment to describe the orbit model