Wildlife and nature: animals, beehives, bushes, flowers, rocks, logs

New stdlib module wildlife.rhai:
- Animals (new palette category): Deer (stag with antlers, does, fawns),
  Wild boar, Fox, Elephant (bull with tusks, cow, calf), Rabbits. Low-poly
  solids from faces (loft, tube), parts drawn back to front by depth, faces
  edged in their own shade (class beast). Herds scatter round a spot, each
  animal its own sprite facing about the object's rotation. Grazing
  animals switch between two head poses (iso-pose2 groups), elephants curl
  their trunks, rabbits hop.
- Birds and Butterflies as flocks: swim() takes a shape (bird, fly, bee);
  wings flap out of step. Fish output unchanged.
- Beehives on stands with supers, lids, entrances and bees flying round;
  Bush (round, flowering, berries); Flowers (bed in rows or meadow); Rocks;
  Log or stump. g-meadow and g-soil ground materials.
- polyline() takes 3D points as documented (antlers).

Theme colours for dark and light, viewer CSS for poses, flapping, hopping.
examples/country: elephants in a paddock with a cut corner, deer at a
forest edge, boar, fox, rabbits, an apiary by a meadow, a pond, a lane,
fence and hedgerow at angles; Country demo in the web Studio and deploy.
MCP guidance, README, SCRIPTING, ROADMAP.

Tests: Rust 78, Studio 122; existing examples draw the same (only the
embedded theme CSS grew).

docs/ROADMAP.md

@@ -83,7 +83,7 @@ Each phase ends with tests, a Studio/viewer check in Edge, commit and push.
 8. Waypoint animation: a person or car moving along a path of waypoints
 9. ~~Build your own house~~ (done, see above)
 10. ~~Diagonal streets, walls, fences, hedges~~ (done, see below)
-11. Wildlife and nature: deer, bushes, beehives and more
+11. ~~Wildlife and nature: deer, bushes, beehives and more~~ (done, see below)
 
 Done since: the middle mouse button only moves the camera; fences and site walls join like house
 walls (`line_joint`); fence designs (mesh, wood, bars, half stone, cobble, brick with pillars);
@@ -132,6 +132,12 @@ against everything on either side. Studio: runs and drags keep to x or y or go d
 (Ctrl: any angle), a road run turning 45° gets a 45° curve, Rotation takes any angle. The
 streets demo has a diagonal lane.
 
+Wildlife and nature (`wildlife.rhai`): Deer, Wild boar, Fox, Elephant, Rabbits as low-poly solids
+(`loft`, `tube`, parts drawn back to front), herds scattered round a spot, two head poses taking
+turns while grazing, rabbits hopping; Birds and Butterflies as flocks (`swim` shapes, wings flapping
+out of step); Beehives with bees, Bush, Flowers (bed or meadow), Rocks, Log / stump.
+`examples/country`, Country demo in the web Studio.
+
 ## Phase 2: richer editing
 
 - [x] Interior prefabs (see Build your own house); a building `rooms` prop is still open