feat(packages): ludic.vehicles - each player's boat and horse: called to four berths or four bays, made the first time and fetched after, owner and rider, mounting (a hungry horse will not go), riding a horse on stamina and a boat on the wind with steering by signed speed, the swell at the edge, getting off onto the rider's own safe spot, a player leaving; the world and the rider through ports; mounted, dismounted, no landing, moved, swell and hunger as facts; this player's own saved by kind

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

packages/ludic.vehicles/mount.ludic

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+# mount.ludic - getting on, and getting off onto a spot the rider's own safe-spot rule found: the
+# same one answer a seat and a stand-up use, so a landing is never inside a boulder or on a bank
+# the body cannot climb off
+export const VEHICLE_HAY_MIN: float = 10.0     # a horse with less hay than this will not go
+
+# this machine's player onto v; false when it is somebody else's, taken, or a hungry horse
+export function vehicle_mount(v: Vehicle) -> bool {
+  if v == null or v.owner != 0 or v.rider >= 0 or ve_cur != null { return false }
+  if v.kind == VEHICLE_HORSE and v.food < VEHICLE_HAY_MIN {
+    ve_say(VEHICLE_HUNGRY, v, v.food)
+    return false
+  }
+  ve_cur = v
+  v.rider = 0
+  VehicleRider.board(v.x, v.z, v.yaw)
+  ve_say(VEHICLE_MOUNTED, v, 0.0)
+  return true
+}
+
+# Off, onto the nearest spot a body could stand and walk off: from a boat a wade of up to 1.25 m
+# within ten metres, from a horse beside its right flank. False (and said) when a boat is too far out.
+export function vehicle_dismount() -> bool {
+  let v = ve_cur
+  if v == null { return false }
+  if v.kind == VEHICLE_BOAT {
+    if not VehicleRider.safe_spot(v.x, v.z, VehicleWorld.water(v.x, v.z), 1.25) {
+      ve_say(VEHICLE_NO_LANDING, v, 0.0)
+      return false
+    }
+    VehicleRider.step_off(VehicleRider.safe_x(), VehicleRider.safe_z())
+  } else {
+    let wx = v.x + Math.cos(v.yaw) * 1.2
+    let wz = v.z - Math.sin(v.yaw) * 1.2
+    if VehicleRider.safe_spot(wx, wz, VehicleWorld.ground(v.x, v.z), 0.0) {
+      VehicleRider.step_off(VehicleRider.safe_x(), VehicleRider.safe_z())
+    } else { VehicleRider.step_off(v.x, v.z) }
+    v.home_x = v.x
+    v.home_z = v.z
+  }
+  ve_cur = null
+  v.rider = -1
+  v.speed = 0.0
+  ve_say(VEHICLE_DISMOUNTED, v, 0.0)
+  return true
+}
+
+# off whatever this player is on, wherever it is (a load, a collapse, a map change)
+export function vehicle_drop() -> void {
+  if ve_cur != null {
+    ve_cur.rider = -1
+    ve_cur.speed = 0.0
+  }
+  ve_cur = null
+}