fix(street-level): review fixes for show_street_level and sl= links

P1: on a phone the Street Level panel sits in the Cameras tab sheet, so the
action and sl= links opened photos nobody could see and still reported
success. A photo that opens, and a link that arms, now open that sheet
(revealPanel). In cockpit, clean view, recording or scene playback the action
stops at a new `view` stage before anything switches or loads.

P2s:
- Mapillary's nearest search asks for 100 photos, the API's most. It cuts
  the radius's photos at the limit in no particular order, so 8 left the
  distance sort and the imagery filter a few arbitrary photos.
- The MCP globe panel opens a billed photo only for a result issued in the
  last five minutes (show_in_gods_eye_view stamps issued_at); a host that
  mounts the panel again hands back the old result, which only arms.
- OPEN uses an armed link's point only while the view centre is within 1 km
  of it; a user who moved on opens what the view shows.
- show_in_gods_eye_view measures a camera's altitude from the terrain under
  it before taking its look-at point, so high cities no longer put the
  photos kilometres too far ahead.
- The armed-link toast is translated, and the new view-stage message too,
  in all 11 catalogs.
- Tests: a turn superseded during the geocode, flight or map switch changes
  nothing; an unknown key state lets a cold sl= link through; a wide tilted
  area still opens photos at its centre.

src/i18n/locales/de.json

@@ -2952,5 +2952,7 @@
   "{source} at {place}": "{source} bei {place}",
   "Street level at {place}": "Straßenebene bei {place}",
   "Switching map": "Karte wird gewechselt",
-  "Opening imagery": "Bilder werden geöffnet"
+  "Opening imagery": "Bilder werden geöffnet",
+  "Street View is ready: press {open} to load it": "Street View ist bereit: Auf {open} klicken, um es zu laden",
+  "Street-level photos are hidden in the current view. Leave it first.": "Fotos auf Straßenebene sind in dieser Ansicht ausgeblendet. Zuerst die Ansicht verlassen."
 }