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).

tools/build_web.py

@@ -150,6 +150,7 @@ def main():
     (web / "house.json").write_text(json.dumps(demo_files("house"), ensure_ascii=False), encoding="utf-8")
     (web / "factory.json").write_text(json.dumps(demo_files("factory"), ensure_ascii=False), encoding="utf-8")
     (web / "streets.json").write_text(json.dumps(demo_files("streets"), ensure_ascii=False), encoding="utf-8")
+    (web / "country.json").write_text(json.dumps(demo_files("country"), ensure_ascii=False), encoding="utf-8")
 
     h = hashlib.sha256()
     for p in sorted((out / "assets").rglob("*")):