pack: track pack/overrides/defaultconfigs/ + ship Waystones override

.gitignore previously ignored all of pack/overrides/ because that dir is
the build output of Build-Tweaks.ps1. But defaultconfigs/ inside it holds
hand-written source-of-truth configs that should be in git (otherwise
they don't survive cross-machine deploys). Whitelisting that subdir.

Adds pack/overrides/defaultconfigs/waystones-common.toml -- the same
file the empty 0.16.1 commit was supposed to ship but couldn't because
of the .gitignore rule. Bumps to 0.16.2.

The override changes just one key:
- spawnInVillages: REGULAR -> DISABLED

All other Waystones settings stay at mod default (ACTIVATION visibility,
PLAYER restriction, empty allowedVisibilities) which already provides
the base-intrusion protections we discussed.

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": "0.16.1",
+  "version": "0.16.2",
   "minecraft": "1.21.1",
   "loader": {
     "type": "neoforge",