chore(pack): make config files opt-in and ship a PetProtect default

.packwizignore ignored config/ and defaultconfigs/ wholesale. They are now
ignored per-entry (config/*) with deliberately authored files re-included at
the bottom of the file, so one config can ship without any risk of pulling
every runtime-generated config into the index - which matters because this
repo doubles as a server directory.

Ships config/petprotect.json disabling BOTH pet damage and death protection.
PetProtect's isInvulnerableTo mixin gates on prevent_pet_damage alone, so
disabling prevent_pet_death by itself leaves pets invulnerable to nearly all
damage and Pet Cemetery's death -> collar -> respawn loop still never fires.
prevent_pet_attack remains true, so pets are not provoked into fights.

Without this file the two mods cancel each other: PetProtect's defaults keep
pets immortal, so Pet Cemetery is dead weight.

The config installs on clients as well as the server; that is harmless since
petprotect itself is side = "server", but packwiz has no per-file side flag
for non-metafile entries.

.packwizignore

@@ -11,10 +11,13 @@ run.sh
 *.jar
 *.jar.log
 run.bat
-# Server/runtime config is never tracked.
-config/
+# Server/runtime config is opt-in. Everything under these directories is
+# ignored; deliberately authored defaults are re-included at the bottom of
+# this file. This repo doubles as a server directory, so a blanket un-ignore
+# here would pull every runtime-generated config into the index.
+config/*
+defaultconfigs/*
 kubejs/
-defaultconfigs/
 local/
 
 # Authoring/review material - belongs in the repo, never in the pack
@@ -40,3 +43,9 @@ cache/
 sp-world/
 *.tar.gz
 *.tgz
+
+# --- Shipped config defaults ----------------------------------------------
+# These must come AFTER every ignore above (last matching pattern wins),
+# including the blanket "*.json" in the authoring section. Re-include only
+# files we deliberately author and want enforced on install.
+!config/petprotect.json