migrate ISO build from Alpine to Debian 12 (Bookworm)

Replace the entire live CD build pipeline:
- Alpine SDK + mkimage + genapkovl → Debian live-build (lb config/build)
- OpenRC init scripts → systemd service units
- dropbear → openssh-server (native to Debian live)
- udhcpc → dhclient for DHCP
- apk → apt-get in setup-builder.sh and build-nvidia-module.sh
- Add auto/config (lb config options) and auto/build wrapper
- Add config/package-lists/bee.list.chroot replacing Alpine apks
- Add config/hooks/normal/9000-bee-setup.hook.chroot to enable services
- Add bee-nvidia-load and bee-sshsetup helper scripts
- Keep NVIDIA pre-compile pipeline (Option B): compile on builder VM against
  pinned Debian kernel headers (DEBIAN_KERNEL_ABI), inject .ko into includes.chroot
- Fixes: native glibc (no gcompat shims), proper udev, writable /lib/modules,
  no Alpine modloop read-only constraint, no stale apk cache issues

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/overlay/usr/local/bin/bee-network.sh

@@ -22,9 +22,8 @@ for iface in $interfaces; do
     log "bringing up $iface"
     ip link set "$iface" up 2>/dev/null || { log "WARN: could not bring up $iface"; continue; }
 
-    # DHCP in background: -b forks if no immediate lease, & ensures non-blocking always.
-    # -t 0: unlimited retries, -T 3: 3s per attempt. No -q: stay running to renew lease.
-    udhcpc -i "$iface" -b -t 0 -T 3 &
+    # DHCP in background — non-blocking, retries indefinitely
+    dhclient -nw "$iface" 2>/dev/null &
     log "DHCP started for $iface (pid $!)"
 done