feat(flights): render on Navara

Task 10b. src/layers/aircraft/render/navara.js implements the aircraft
renderer contract on the engine contract alone (no three, no Cesium):
- Fleet glyphs: banks of engine.movers sprite sets (one per distance scale
  and depth mode the handles ask for; flights: one, 'always', Cesium's
  NearFarScalar), growing by doubling, from a glyph atlas of every
  aircraftIcon() kind at the fleet (64 px) and tracked (192 px) rasters
  (data/aircraftIcons: AIRCRAFT_ICON_KINDS, aircraftIconCells,
  aircraftIconAtlasLayout, drawAircraftIconAtlas). Sprite handles keep the
  Billboard field vocabulary as setters; a frame's writes commit once at
  the end of the frame listener that made them (a microtask outside one).
- Models: banks of model mover sets per glTF and look; handles report
  ready from MoverSet.ready() and computedScale from minimumPixelSize kept
  on the CPU (radiusM in the spec, the class's nativeRadiusM); poses are
  Cesium's HPR frame (modelMatrix) turned by Navara's glTF axes
  (Z_UP_TO_X_UP: its loader is already Z-up; chosen side by side with
  Cesium among six candidates).
- Tracked glyph: a sprite whose position/colour/rotation callbacks are read
  every frame in preRender; follow = engine.camera.follow with the tracked
  readout's card as its label (gevFollowHandle); current() maps the follow
  back to the tracked handle, also while follow() raises followChanged.
- Trail and live head: engine.lines (alpha 0.85, depth-fail 0.4, geodesic)
  in the gev-trail pick namespace.
- View: camera/scene adapters over engine.camera.pose() (registered with
  the engine so shared helpers project through it), frustum and horizon
  tests, frame number, engine frame events.
flights/render/navara.js registers it for 'navara' from the Navara mode's
import(); the Navara catalog now offers Live Flights.

Also: tracking a contact that is selected but no longer followed follows it
again (a camera command ends a Navara follow; on Cesium a search flight
releases trackedEntity): trackById/select re-follows instead of only
re-publishing. Behaviour change on Cesium only in that case.

Tests: the renderer on the fake engine (contract, atlas, banks, per-frame
commits, growth, tracked callbacks, follow label, model pose, trails) and
the flights logic over it (fleet, click-select, follow, re-follow after a
camera command, release, no set left behind).

scripts/package-boundaries.json

@@ -2592,7 +2592,9 @@
       "src/layers/aircraft/render/cesium.js",
       "src/layers/flights/render/cesium.js",
       "src/data/selectionDispatcher.js",
-      "src/layers/shared/color.js"
+      "src/layers/shared/color.js",
+      "src/layers/aircraft/render/navara.js",
+      "src/layers/flights/render/navara.js"
     ],
     "external": [
       "hls.js",