fix: restore tree dropped by 6d224861; land stem95su gdrive-sync (10m) [ci skip]

6d224861 came from a --no-checkout worktree whose empty index made the
commit drop every file except two. This restores 05b50d2b's full tree and
correctly adds stacks/stem95su/gdrive-sync.tf + the service-catalog stem95su
entry. Forward-only (parent=6d224861, no force-push); [ci skip] since the
live infra was never applied from the broken commit.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/nfs-change-tracker.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=Track NFS filesystem changes for incremental offsite backup
+After=local-fs.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/inotifywait -m -r \
+    --format '%%w%%f' \
+    -e create -e modify -e moved_to -e delete \
+    --exclude '(/\..*swp$|/\.nfs|/\.Trash|\.db-shm$|\.db-wal$|\.db-journal$|/stats/.*\.stat$|^/srv/nfs/anca-elements/)' \
+    /srv/nfs \
+    /srv/nfs-ssd
+StandardOutput=append:/mnt/backup/.nfs-changes.log
+StandardError=journal
+Restart=always
+RestartSec=10
+
+[Install]
+WantedBy=multi-user.target