Fix SSH password auth in Proxmox VM cloud-init

Arch Linux cloud images disable SSH password authentication by default.
Added cloud-init directives to:
- Enable ssh_pwauth
- Set the darkforge user password via chpasswd (plaintext, non-expiring)
- Write /etc/ssh/sshd_config.d/99-darkforge.conf enabling PasswordAuthentication
- Restart sshd after config is written

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/proxmox/create-vm.sh

@@ -126,6 +126,23 @@ mkdir -p "${SNIPPET_DIR}"
 
 cat > "${SNIPPET_DIR}/darkforge-test-init.yaml" << 'CLOUDINIT'
 #cloud-config
+
+# Enable SSH password authentication (cloud images disable it by default)
+ssh_pwauth: true
+chpasswd:
+  expire: false
+  users:
+    - name: darkforge
+      password: darkforge
+      type: text
+
+# Ensure sshd allows password auth
+write_files:
+  - path: /etc/ssh/sshd_config.d/99-darkforge.conf
+    content: |
+      PasswordAuthentication yes
+      PermitRootLogin no
+
 package_update: true
 packages:
   - base-devel
@@ -147,6 +164,9 @@ packages:
   - tmux
 
 runcmd:
+  # Restart sshd to pick up the password auth config
+  - systemctl restart sshd
+
   # Grow the partition to fill the disk
   - growpart /dev/sda 2 || true
   - resize2fs /dev/sda2 || btrfs filesystem resize max / || true