playbooks: fix drop-in filename collision in esh NFS boot-ordering

override.conf already existed on esh-docker-vm (dockerd ExecStart), so
the creates: guard skipped the step and the After=remote-fs.target
directive was never written. Use a distinct filename
(10-after-remote-fs.conf) that systemd merges alongside override.conf,
and guard on content rather than file existence so a stale file can't
silently skip.

playbooks/fix-esh-nfs-boot-ordering.yaml

@@ -38,12 +38,17 @@ steps:
     when: "grep -qE '^10\\.0\\.50\\.50:.* nfs defaults ' /etc/fstab"
 
   - name: Install docker.service drop-in to order after remote-fs.target
+    # Use a DISTINCT filename — esh-docker-vm already ships an
+    # override.conf (dockerd ExecStart/containerd socket); systemd merges
+    # all *.conf drop-ins, so a separate file augments rather than
+    # clobbers it. Guard on CONTENT, not file existence, so a stale/empty
+    # file can't make this silently skip.
     shell: |
       install -d -m 0755 /etc/systemd/system/docker.service.d
       printf '[Unit]\nAfter=remote-fs.target\nWants=remote-fs.target\n' \
-        > /etc/systemd/system/docker.service.d/override.conf
+        > /etc/systemd/system/docker.service.d/10-after-remote-fs.conf
     sudo: true
-    creates: /etc/systemd/system/docker.service.d/override.conf
+    when: "! grep -qs remote-fs.target /etc/systemd/system/docker.service.d/10-after-remote-fs.conf"
 
   - name: Reload systemd so the drop-in takes effect next boot
     shell: systemctl daemon-reload