fix(cctv): on a globe map the camera plane ends where the view meets the ground

The activation probe raycast only the photoreal tiles. On a globe map the ray
missed, or ran on through the Earth and met a primitive thousands of
kilometres away, and the monitor plane stood at the camera's full range:
about a kilometre wide and hundreds of metres up. A hit at or beyond the range
now counts as none, and on a globe map the plane also clamps short of the
globe's terrain along the axis, or flat ground at the mount's ground while
that terrain is still loading, whichever is nearer.

docs/CURRENT-STATE.md

@@ -6570,6 +6570,10 @@ silently demoting every later lookup for the session.
   far cap, retargeting the existing video/canvas texture pipeline. Stills are drawn at their source aspect, centered on the placeholder dark (`#01070c`), instead of being stretched to the 16:9 canvas. Manual calibration only —
   auto-calibration and the drape mesh pipeline are deleted. A one-shot activation obstruction
   probe (`pickFromRay` on camera activation, clamping the plane short of the first hit) remains;
+  a hit at or beyond the camera's range counts as a miss, and on a globe map the plane also clamps
+  short of the globe's terrain along the axis (flat ground at the mount's ground when terrain is
+  missed or met beyond the range), whichever is nearer, so it never stands at the full range there
+  (about a kilometre wide and hundreds of metres up);
   ground placement is superseded by the shared-floor v3 behavior below. Calibration persists to
   `godsEyeView.cctv.calibration.v2` (wiped clean, no v1 import); a panel-only CAL badge shows
   `CALIBRATED`/`CURATED`/`RAW PRIOR` (no in-world tint). Panel is titled "CCTV" (not "CCTV