feat(mapillary): street-level layer core — coverage, sequences, viewer bridge, query engine

Camera-driven Mapillary coverage (z0–5 overview points from orbit, z11–14
ground-clamped sequence lines below 60 km), per-sequence image cones, an
embedded MapillaryJS viewer bridge with a camera-follow mode, sprite icons
for map features, and a query engine that turns a plan into a streamed
z14 tile fan-out. Registers an on-globe CC BY-SA 4.0 credit while enabled.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

src/app/catalog.js

@@ -4,6 +4,7 @@ const CONTROL_LAYER_IDS = Object.freeze({
   militaryFlightsLayer: 'military',
   satellitesLayer: 'satellites',
   cctvLayer: 'cctv',
+  mapillaryLayer: 'mapillary',
   radioLayer: 'radio',
   bikeshareLayer: 'bikeshare',
   transitLayer: 'transit',