pack: KubeJS Waystones policy (1-per-player + ban share/portstones)

Adds pack/overrides/kubejs/server_scripts/waystones_policy.js which:

- Caps regular waystones at 1 per player. Per-player count is stored in
  player.persistentData and decremented on break (works correctly because
  restrictedWaystones = ["PLAYER"] means only owners can break).
- Bans all 16 sharestone variants. They defeat the "build transport"
  intent (solo pair-teleport) and can be placed just outside a claim
  for stealth proximity access.
- Bans all 16 portstone variants pending separate design review.
- Leaves warp plates and warp scrolls untouched.

Bumps to 0.17.0 so launcher re-syncs.

pack/pack.lock.json

@@ -1,7 +1,7 @@
 {
   "$schema": "Brass-and-Sigil pack.lock.json - generated, do not edit by hand unless you know what you are doing",
   "name": "Brass and Sigil",
-  "version": "0.16.3",
+  "version": "0.17.0",
   "minecraft": "1.21.1",
   "loader": {
     "type": "neoforge",