feat: add Debian 13 golden image Packer pipeline and cloud-init bootstrap

ci/packer/cidata/meta-data

@@ -0,0 +1,2 @@
+instance-id: apex-golden-image-build
+local-hostname: apex-builder

ci/packer/cidata/user-data

@@ -0,0 +1,14 @@
+#cloud-config
+ssh_pwauth: true
+disable_root: false
+chpasswd:
+  list: |
+    debian:packer
+    root:packer
+  expire: false
+users:
+  - default
+  - name: debian
+    sudo: ALL=(ALL) NOPASSWD:ALL
+    shell: /bin/bash
+    lock_passwd: false