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.

crates/isokit-project/src/mcp.rs

@@ -27,8 +27,9 @@ Fences (props.style: mesh, wood, bars, half stone, cobble, brick) and site walls
 meet, so for a plot boundary put each piece's ends exactly on the next piece's end or line. Line pieces (roads, walls, \
 fences, hedges, house walls) can run at any angle: a piece from (x0, y0) to (x1, y1) has x, y = the midpoint, \
 w = the distance and rot = atan2(y1 - y0, x1 - x0) in degrees; where diagonal pieces meet, corners are mitred. \
-Animals (category Animals: deer, boar, fox, elephant, rabbits, birds, butterflies) are herds: props.n animals \
+Animals (category Animals: deer, boar, fox, elephant, rabbits, hamster, birds, butterflies) are herds: props.n animals \
 scattered within props.r metres of x, y, facing about the rotation; keep them out of roads, ponds and buildings. \
+Hamsters are life size (props.scale makes giants); a hamster_wheel (props.diameter, 0.3 m) has one running in it. \
 A route (type route) moves props.n movers (props.kind: car, bus, motorbike, cyclist, person, deer, elephant) along \
 waypoints pts (relative to x, y): round them when props.closed, else there and back; each way keeps to the left \
 of the line (props.keep). For traffic, put the points on the road centre lines; keep routes clear of buildings. \