fix: close OVA build gaps — 24.04, overlay copy, full compose stack

- Replace ubuntu-26.04 (unreleased) with ubuntu-24.04 LTS throughout
- Add file provisioner to Packer HCL to copy overlays/ into VM before
  provisioning (fixes missing zroc-setup binary in 03-setup-wizard.sh)
- Rebuild root docker-compose.yaml: full stack with env vars — Caddy,
  zroc-ui, Authentik (server + worker + postgres + redis), Prometheus,
  Grafana, Zerto exporter, Watchtower; no hardcoded credentials
- Add caddy/Caddyfile to repo root for reverse proxy / TLS
- Update 02-zroc.sh to pre-pull all service images during OVA build
- Update GitHub Actions workflow to reference ubuntu-2404.pkr.hcl

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

zroc-ova/.github/workflows/build-ova.yml

@@ -31,7 +31,7 @@ jobs:
           fi
           echo "version=$VERSION"   >> $GITHUB_OUTPUT
           echo "tag=v$VERSION"      >> $GITHUB_OUTPUT
-          echo "ova_name=zroc-appliance-${VERSION}-ubuntu-26.04-amd64.ova" >> $GITHUB_OUTPUT
+          echo "ova_name=zroc-appliance-${VERSION}-ubuntu-24.04-amd64.ova" >> $GITHUB_OUTPUT
 
       - name: Install Packer
         run: |
@@ -42,7 +42,7 @@ jobs:
 
       - name: Packer init
         working-directory: packer
-        run: packer init ubuntu-2604.pkr.hcl
+        run: packer init ubuntu-2404.pkr.hcl
 
       - name: Validate
         working-directory: packer
@@ -50,7 +50,7 @@ jobs:
           packer validate \
             -var "vm_version=${{ steps.ver.outputs.version }}" \
             -var-file=variables.pkrvars.hcl \
-            ubuntu-2604.pkr.hcl
+            ubuntu-2404.pkr.hcl
 
       - name: Build OVA
         working-directory: packer
@@ -62,7 +62,7 @@ jobs:
             -var "vm_version=${{ steps.ver.outputs.version }}" \
             -var "headless=true" \
             -var-file=variables.pkrvars.hcl \
-            ubuntu-2604.pkr.hcl
+            ubuntu-2404.pkr.hcl
 
       - name: Locate OVA
         id: ova