Require a factory snapshot to reset a computer (#6680)

Machines without @factory fell back to a degraded reset that kept the
current system and only wiped user state. Turn them away with an
explanation instead, and drop the degraded staging path.

The first-boot worker still honors a wipe-degraded marker so a reset
staged by an older version finishes its scrub rather than handing the
machine over with the seller's accounts intact.

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

install/user/mise-work.sh

@@ -22,7 +22,7 @@ if [[ -n $NODE_PACKAGE_DIR ]]; then
   NODE_TARBALL=$(find "$NODE_PACKAGE_DIR" -name "node-v*-linux-x64.tar.gz" -type f 2>/dev/null | head -n1)
   if [[ -z $NODE_TARBALL ]]; then
     if [[ ${OMARCHY_SETUP_CONTEXT:-} == "provision-owner" ]]; then
-      # A degraded reset on an old install may not have the tarball staged.
+      # A factory snapshot predating the bundled tarball may not have it staged.
       # Leave Node to the network rather than failing the whole first boot.
       echo "Warning: no bundled Node.js tarball in $NODE_PACKAGE_DIR; trying the network" >&2
       mise use -g node@latest || echo "Warning: Node.js install deferred (no network)" >&2