feat(vehicles): 16.7 - a boat is a buoyant hull in the game's physics (VehicleHull), rowed along its bow and turned by the oars; the scripted bob, the wind's drift and the shore refusal are gone

The water floats the hull, the wind pushes every boat as a force, the lake bed stops it at the shore;
the swell takes the outward share of a stroke. ludic.physics: phys_hull_add (a buoyant box),
phys_row, phys_bow_speed, and a test that floats one a quarter under, rows, turns and grounds it.
The vehicles tests row a real Jolt hull on the fake shore; the horse moved to horse.ludic.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.vehicles/kinds.ludic

@@ -14,7 +14,6 @@ export property Vehicle {
   fuel: float = 0.0       # a horse's stamina, 0..100
   food: float = 0.0       # a horse's hay, 0..100
   seat_h: float = 0.0     # the rider sits this far above it
-  bob: float = 0.0
   owned: bool = false     # hired or rented for the trip
   owner: int = 0          # the player it belongs to (0: this machine's)
   rider: int = -1         # the player on it, -1 nobody