fix(dev-vm): forward port 8080 to expose kubeconfig HTTP from QEMU

90-kubesolo.sh starts an nc-based HTTP server on port 8080 inside the
VM to serve the admin kubeconfig (serial console truncates the
base64-encoded cert lines, so HTTP is the reliable retrieval path).
hack/dev-vm-arm64.sh only forwarded ports 6443 (kube-apiserver) and
2222 (ssh), so `curl http://localhost:8080` from the Mac returned
empty — the connect attempt landed on a closed Mac-side port.

Add the third hostfwd. Now `curl http://localhost:8080` from the host
machine reaches the in-VM HTTP server and returns the kubeconfig.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hack/dev-vm-arm64.sh

@@ -133,7 +133,7 @@ if [ "$MODE" = "disk" ]; then
         -bios "$UEFI_FW" \
         -drive "file=$DISK_IMAGE,format=raw,if=virtio,media=disk" \
         -net "nic,model=virtio" \
-        -net "user,hostfwd=tcp::6443-:6443,hostfwd=tcp::2222-:22"
+        -net "user,hostfwd=tcp::6443-:6443,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:8080"
     exit 0
 fi
 
@@ -199,4 +199,4 @@ qemu-system-aarch64 \
     -append "console=ttyAMA0 kubesolo.data=/dev/vda kubesolo.debug $EXTRA_APPEND" \
     -drive "file=$DATA_DISK,format=raw,if=virtio" \
     -net "nic,model=virtio" \
-    -net "user,hostfwd=tcp::6443-:6443,hostfwd=tcp::2222-:22"
+    -net "user,hostfwd=tcp::6443-:6443,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:8080"