Enhance provisioning documentation and scripts for improved network boot and DNS management</message>

<message>Add new documentation files for device DNS management via DHCP and dnsmasq configuration. Update cloud-init scripts to ensure proper handling of /etc/resolv.conf and DNS settings, allowing for seamless integration with file.server. Modify existing scripts to support dynamic LAN subnet configuration and improve overall network boot functionality. These changes enhance user experience and streamline the setup process for the CM4 eMMC provisioning service.

emmc-provisioning/cloud-init/user-data.bootstrap

@@ -5,6 +5,9 @@
 #    provisioning portal or file server). Example: http://10.20.50.1:5000/files/bootstrap.sh
 # 2. Copy this file to the boot partition as "user-data" (with meta-data and optional network-config).
 # 3. Edit BOOTSTRAP_URL below to match your server (or set it once in the runcmd section).
+#
+# DNS: This config uses systemd-resolved; /etc/resolv.conf is a stub and DNS comes from DHCP
+# (LXC option 6). Ensure bootstrap.sh does not overwrite /etc/resolv.conf. See docs/DEVICE-DNS-DHCP-RESOLVCONF.md.
 
 package_update: true
 package_upgrade: false
@@ -99,7 +102,7 @@ runcmd:
   - systemctl start ssh
   # Download and run bootstrap script (edit URL to match your file server)
   - |
-    BOOTSTRAP_URL="http://10.20.50.1:5000/files/bootstrap.sh"
+    BOOTSTRAP_URL="http://file.server:5000/files/bootstrap.sh"
     LOG="/var/log/cloud-init-bootstrap.log"
     if ! curl -fsSL "$BOOTSTRAP_URL" -o /tmp/bootstrap.sh 2>>"$LOG" || [ ! -s /tmp/bootstrap.sh ]; then
       echo "$(date -Iseconds) ERROR: Failed to download bootstrap.sh from $BOOTSTRAP_URL (file missing or empty)" >> "$LOG"