The same bug the camera had, still live in the default light rig

Three loose ends turned into four, because one of them was not a stale comment.

`cityDaylight()` closed its fog at 210/460 — numbers tuned when San Francisco's
230-unit board was the only one. Every caller who supplies an `Atmosphere`
overrides them, which is why this survived: the demo does, so nothing looked
wrong. A self-hoster who renders a city with no clock and no weather gets the
default path, and on the Bay Area's 1003 units that fog closes well inside the
city. It now scales to the board exactly as the camera limits do, with the old
constants preserved as the default for a caller holding a palette but no world.

The three that really were comments: socal.ts justified its `latScale` by
citing the 340-unit orbit cap and the 460-unit fog as things the engine
insisted on, and the engine stopped insisting when both became board-relative —
285 is now a choice the pack makes because its lot sizes and hill radii were
authored against it. CONTRACT.md and ARCHITECTURE.md still measured the
retention argument against a 336,864-point San Francisco that has been the
whole Bay Area for some time. And server/package.json listed five routes where
there are six.

None of these changed behaviour except the first. All of them would have gone
on quietly disagreeing with the pages that now cite them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

ARCHITECTURE.md

@@ -214,7 +214,8 @@ receiver as the eventual real answer.
 ## 5. LA is not "SF but more data"
 
 SF is 0.20° × 0.36°. At the 45 m cells the SF heightfield uses, that is 336k
-lattice points and a 1.0 s build.
+lattice points and a 1.0 s build. (The pack has since grown to the whole Bay
+Area: 0.53M points and about 2.3 s.)
 
 LA + Orange County + Riverside is roughly 0.5° × 1.9° — about **14× the area**.
 The same approach would be 4.6M lattice points and a mesh nobody can load. This
@@ -293,7 +294,8 @@ resolutions:
   puts one scene unit at ~94 m with 3.6× vertical exaggeration; an office renders
   at 1 unit = 1 m. There are two scenes over one renderer, and the city scene is
   *retained and paused* when you step inside rather than disposed — rebuilding
-  its 336,864-point heightfield costs about a second on the way back out.
+  its 0.53M-point heightfield costs about two and a half seconds on the way back
+  out.
 - **A person at a desk is not a `Marker`.** A marker is geographic — it has a
   lat/lng. Presence binds to a **seat id** and never to a coordinate, which is
   what lets the office geometry be public and open-source while who is sitting