SoCal, the whole bay, a moon, and gates that actually run

Six agents in parallel, and the two city packs independently reported the same
blocker: `focusRegions` and `coarseFactor` existed on the `City` type and
nothing implemented them. Uniform lattices would have been 2.9M points for
Southern California and 3.7M for the expanded bay. Both packs were unloadable
as written.

`buildAxis` is the answer, and it is honest about its limits: refinement is per
axis, not per rectangle, so a focus region sharpens its whole row *and* its
whole column. Two regions at opposite corners refine nearly everything between
them. Measured, not guessed — the bay went 0.53M points with one region and
1.64M with three, for detail nobody is looking at from a board this wide. One
region each, coarse factor ten, and the builds land at 3.8 s and 2.3 s.

Then three things that were only ever right because San Francisco was the only
city. `maxDistance: 340` and a 170-unit shadow box were constants tuned for a
230-unit board; the bay is 1003 units across and the camera physically could
not retreat far enough to frame it. Fog distances were scene units pinned to
the same assumption. And `minVisibilityM` defaulted to 4.5 km of honest
weather, which over ninety-four kilometres of bay correctly hides three
quarters of it — the night view was a black rectangle for a completely
reasonable reason. All three now derive from the board.

The moon is a real ephemeris and its light is a deliberate lie: 1.15, against a
physical ratio of one to four hundred thousand. What is being reproduced is
what a moonlit night looks like on a screen in a lit room.

The CI gate caught itself, which is the part worth keeping. Port 8431 was
already held by a server from an earlier session, so the boot check polled a
healthy stranger while the process it started died on EADDRINUSE. It now
refuses to run rather than pass.

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

.gitignore

@@ -6,3 +6,22 @@ dist/
 # runtime and cached in the browser. An Apache-2.0 repo containing them would
 # be relicensing marks it does not own. See ARCHITECTURE.md §3.1.
 public/logos/
+
+# ---- Self-hoster space ----
+#
+# Yours, not ours. Drop your own props, kits, office packs and notes here and
+# nothing in this repo will look at them, complain about them or ship them.
+#
+# This is the other half of the no-binary-art gate. That check
+# (scripts/check-no-binaries.mjs) enumerates with `git ls-files` and is strict
+# only over src/**, so your own legally-clean .glb sitting in public/props/ is
+# invisible to it and cannot fail your build — an earlier design walked the
+# working tree and would have. Ignoring these paths is what makes that promise
+# hold by default rather than by everybody remembering. See CONTRACT.md §7.
+#
+# Worth knowing before you write one: docs/ is in here too, so documentation
+# committed to this repo lives at the root or beside the code it describes.
+public/props/
+public/kits/
+public/offices/
+docs/