Wildlife: hamster and hamster wheel prefabs

Ported from the thaiai.lol easter egg (thaiai iso/hamster/lib/hamster.rhai);
the data-centre joke parts stay there.

- hamster (Animals): golden, grey or cream with a white belly, pink nose,
  ears and paws, buck teeth and whiskers; standing, running on the spot or
  asleep (eyes shut, z Z); n and spread like the herds; life size (about
  17 cm) at scale 1, up to 40 times.
- hamster_wheel (Animals): diameter (0.3 m life size, up to 12 m), running,
  A-frame stand or a cage-wall axle stub, fur colour. Running legs and the
  rungs are flipbooks of 4 poses, 0.1 s each; the spokes turn by a CSS
  rotation in a matrix that maps the wheel's plane onto the screen.
- draw_parts learns loft2 (two-tone lofts), eye and flip parts;
  place_parts scales and moves any part list; loft and loft2 share
  loft_rings (the other animals draw byte for byte as before).
- Things under 2 m are drawn ten times bigger in a group that scales them
  back (fine_begin / fine_end), so a life-size hamster keeps its shape on
  the drawing's 0.1-unit grid; sort boxes stay real size.
- The legs push back on the ground and swing forward lifted (the original
  lifted them on the way back).
- Theme: hamster, hamsterg, hamsterc, hamsterw, hamsterp, hwheel, hwhub,
  whisker and hamz in both palettes, materials, rules for eyes, whiskers,
  rims, spokes, hub, rungs and the z Z. Viewer CSS: iso-flip4,
  iso-wheelspin, iso-runbob, iso-zzz; beast edges take --bw (default .3).
- Test hamsters_run_in_wheels_from_every_side: no sort cycles in any
  rotation, flipbook counts, scaled groups, real-size sort boxes, tooltips.
- README, ROADMAP, SCRIPTING and the MCP instructions list them.

README.md

@@ -83,15 +83,17 @@ swimming round under lily pads, ripples and reeds; trees, hedges and rows of
 trees are in Nature.
 
 **Animals and nature**: Deer (a herd of a stag, does and fawns, or one
-kind), Wild boar, Fox, Elephant (bull, cow, calf), Rabbits, a flock of Birds
-circling and Butterflies; Beehives on stands with bees flying round, Bushes
-(round, flowering, berries), Flowers (a bed in rows or a wildflower meadow),
-Rocks and a Log or stump. Animals are low-poly solids that read from every
-side; a herd scatters about the object's spot, each animal its own sprite.
-Grazing animals lower and raise their heads in turn, elephants curl their
-trunks, rabbits hop, birds flap. `examples/country` (Country demo in the web
-Studio) puts them in a countryside corner with a lane, fence and hedgerow at
-an angle.
+kind), Wild boar, Fox, Elephant (bull, cow, calf), Rabbits, Hamsters (golden,
+grey or cream; life size, or scaled up for a giant) and a Hamster wheel with
+one running in it, a flock of Birds circling and Butterflies; Beehives on
+stands with bees flying round, Bushes (round, flowering, berries), Flowers (a
+bed in rows or a wildflower meadow), Rocks and a Log or stump. Animals are
+low-poly solids that read from every side; a herd scatters about the
+object's spot, each animal its own sprite. Grazing animals lower and raise
+their heads in turn, elephants curl their trunks, rabbits hop, hamsters run
+(legs and the wheel's rungs step through four poses, the spokes turn), birds
+flap. `examples/country` (Country demo in the web Studio) puts them in a
+countryside corner with a lane, fence and hedgerow at an angle.
 
 **Routes**: a Route moves cars, buses, motorbikes, cyclists, people, deer or
 elephants along waypoints. Pick Route and click point after point on the map