Add web installer and deploy templates

Introduce a web-based deployment helper and supporting templates to automate environment sync, validation, build, and service restarts. Adds deploy/installer/index.php (installer UI and orchestration), deploy/templates/nginx-votersalert.conf.tpl and deploy/templates/supervisor-votersalert-campaign-worker.conf.tpl (generated config templates), and updates .gitignore to exclude .env, .env.backup, and deploy/generated/. Also updates DEPLOYMENT_AAPANEL.md with instructions for running the installer, generated file locations, and a security note to remove or restrict the installer after use.
