fix: leave world settings alone on a wipe, and snapshot them first

Reverts the restore-from-template behaviour. A wipe now resets the world and the
player database only; Server/<name>_{SandboxVars,spawnregions,spawnpoints}.lua
carry over untouched, so hand tuning survives it. Verified by checksum: all three
files byte-identical either side of a wipe.

That gives up the guarantee the restore bought. PZ writes the running world's
settings back over those files, so if a world is ever created with defaults the
file inherits them and later wipes regenerate from them -- which is how a Sophie
world became an Apocalypse one. Nothing corrects that automatically now, so the
wipe takes a snapshot of the settings before it starts, keeping the last ten
under config-backup/. Greg's edits were lost once because the only record of them
was a file the server had since overwritten; that is the hole this fills.
config-template/ still holds the pristine Sophie preset to copy back from.

The snapshot is best-effort throughout. The first version of it created the
directory with plain mkdir, the parent belongs to the container's subuid rather
than the podman user, and set -e turned that into a failed wipe -- the same shape
as the tee that broke this script before. Ansible owns the directory now and
every step of the snapshot tolerates failure, because a backup that cannot be
written is not a reason to refuse to wipe.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ansible/roles/podman/templates/zomboid/world-reset.sh.j2

@@ -32,6 +32,28 @@ if podman unshare test -f "$TRIGGER_FILE"; then
     podman unshare rm -f "$TRIGGER_FILE"
 fi
 
+# Snapshot the current settings before touching anything. They are not modified
+# by the wipe, but they are the one thing here with no other copy: Greg's edits
+# were lost once already because the only record of them was a file the server
+# had since overwritten.
+# Every step here is best-effort: a wipe must never fail because a backup could
+# not be written. An unwritable log aborted this whole script once already.
+SNAP_DIR="{{ podman_home }}/.local/share/volumes/zomboid/config-backup/$(date '+%Y-%m-%d_%H-%M-%S')"
+if ! mkdir -p "$SNAP_DIR" 2>/dev/null; then
+    log "WARNING: could not create $SNAP_DIR; skipping settings snapshot"
+    SNAP_DIR=""
+fi
+if [[ -n "$SNAP_DIR" ]]; then
+    for f in SandboxVars spawnregions spawnpoints; do
+        src="{{ podman_home }}/.local/share/volumes/zomboid/data/Server/${SERVER_NAME}_${f}.lua"
+        podman unshare cp "$src" "$SNAP_DIR/${f}.lua" 2>/dev/null || true
+    done
+    log "Settings snapshotted to ${SNAP_DIR##*/}"
+    # Keep the last 10 snapshots.
+    ls -1dt "{{ podman_home }}/.local/share/volumes/zomboid/config-backup"/*/ 2>/dev/null \
+        | tail -n +11 | xargs -r rm -rf || true
+fi
+
 # Stop server
 log "Stopping zomboid service..."
 systemctl --user stop zomboid.service || true
@@ -55,23 +77,16 @@ else
     log "No database found at $DB_PATH"
 fi
 
-# Restore the intended world settings before the server regenerates.
+# Settings are deliberately NOT touched here. A wipe resets the world and the
+# players; Server/<name>_{SandboxVars,spawnregions,spawnpoints}.lua carry over
+# as-is, so hand-tuned settings survive it.
 #
-# Without this the wipe silently changes the game. PZ writes the running world's
-# settings back over Server/<name>_SandboxVars.lua, so by the time we delete the
-# save that file already describes the world we are throwing away -- and if that
-# world had defaults, the replacement inherits them. Restoring from the canonical
-# copy is what makes a wipe reset the world and keep the settings.
-CONFIG_TEMPLATE="{{ podman_home }}/.local/share/volumes/zomboid/config-template"
-SERVER_DIR="{{ podman_home }}/.local/share/volumes/zomboid/data/Server"
-for f in SandboxVars spawnregions spawnpoints; do
-    if [[ -f "${CONFIG_TEMPLATE}/${f}.lua" ]]; then
-        podman unshare cp "${CONFIG_TEMPLATE}/${f}.lua" "${SERVER_DIR}/${SERVER_NAME}_${f}.lua"
-        log "Restored ${SERVER_NAME}_${f}.lua from canonical config"
-    else
-        log "WARNING: no canonical ${f}.lua; the new world will inherit whatever the server last wrote"
-    fi
-done
+# The risk that buys: PZ writes the running world's settings back over those
+# files, so if a world is ever created with defaults the file inherits them and
+# every later wipe regenerates from them -- which is how a Sophie world became an
+# Apocalypse one. Nothing here corrects that automatically any more, so the
+# snapshot above is the way back: config-backup/ holds the settings as they were
+# before each wipe, and config-template/ holds the pristine Sophie preset.
 
 # Start server
 log "Starting zomboid service..."