- Rework share/import into one Dialog (matches rename/create): a single code
field (copy to share, paste + Load to import) with a hover copy button, a
Reset link beside the upload icon when viewing an imported map, and plainer
copy.
- Core orb: scales with the world zoom (~1.25× the inner shell), backdrop wash
behind it; on focus/hover the scene composites above the orb so the active
tooltip + lit lines are never covered.
- fitViewport floors zoom at the reference (5-ring) extent, so big maps render
at a constant scale and pan instead of shrinking every node to fit.
- Light mode: flip inter-ring band shading to read as depth (not a mound),
fade the core ring in from t=0, drop the timeline star glow.
- Timeline: filled play glyph, crisper constellation, date moved into the legend.