City mode now renders as a night scene: exponential fog into a dark sky
tuned per camera, brighter neon edges, and procedural window grids on
every wall whose lit share grows with the file's definition count.
Selecting a file draws animated screen-space ribbons from each importer
to each imported building, arcing higher with distance: cyan and solid
for known links, amber and dashed for inferred ones. Search hits raise
light columns over their buildings so matches are visible across the
city. Both effects are additive and never occlude. District names hide
when the helicopter is close.