fix(import): correct clamping and bound local-file rendering

Normalize GeoJSON ground footprints, preserve explicit KML track heights,
and tessellate ground paths before native loading. Validate coordinates,
geometry types and decoded image budgets before allocating native resources;
strip loader-sensitive metadata and settle deferred failures and cancellation.

Render static pins in owned billboard collections instead of walking tens
of thousands of point entities each frame. Refine nearby ground heights in
batches, isolate imported pins from height picks, and release owned resources
and point selections on removal. Use safe ray origins above a hidden coarse
globe and retain valid mesh heights outside the current footprint.

Frame complete geometry with viewport-aware nadir arrivals, including walls
and rotated overlays; respect camera gestures and accept document file drops.
Strengthen real-loader, native 3D Tiles, paint, clock and lifecycle coverage.
Addresses both P1 and all 25 P2 findings in the follow-up review of #1122.

src/locations.js

@@ -1,3 +1,4 @@
+import { rangeForBoundingSphere } from './data/cameraFraming.js';
 import { isUnavailableCapability } from './sources/capability.js';
 import { createOverpassFeatureSource } from './sources/overpassFeatures.js';
 import { applicationServices } from './services/application.js';
@@ -1377,19 +1378,6 @@ function buildingBoundingRadius(bounds) {
   return Math.hypot(halfHeight, halfWidth, halfDepth) * 1.18;
 }
 
-function rangeForBoundingSphere(viewer, radius) {
-  const frustum = viewer.camera.frustum;
-  const verticalFov = Number(frustum?.fov) || Cesium.Math.toRadians(60);
-  const aspectRatio = Math.max(0.5, Number(frustum?.aspectRatio) || 1);
-  const horizontalFov = 2 * Math.atan(Math.tan(verticalFov / 2) * aspectRatio);
-  const limitingFov = Math.min(verticalFov, horizontalFov);
-  // Target 57% sphere occupancy so perspective still leaves at least 40%
-  // measured roof-to-base breathing room in ordinary oblique building views.
-  const occupiedViewportFraction = 0.57;
-  const desiredAngularRadius = (limitingFov * occupiedViewportFraction) / 2;
-  return (radius / Math.sin(desiredAngularRadius)) * 1.05;
-}
-
 function buildingPitch(bounds) {
   if (!bounds) return -25;
   const footprint = Math.max(bounds.width, bounds.depth);