Unify reverse proxy handling across apps via sys-stk-front-proxy and cleanly separate internal docker nginx configs from external vhosts.
Changes:
- docker-compose: use with_first_found for optional env and docker-compose.override files so roles can provide either a template or a static file without noisy 'Could not find or access' failures.
- sys-stk-front-proxy: remove front_proxy_domain_conf_src and switch nginx vhost rendering to with_first_found over app-specific proxy.conf.j2 and the generic roles/sys-svc-proxy vhost flavour; keep health-check and handler logic unchanged.
- web-app-nextcloud: migrate to sys-stk-full-stateful (front proxy + DB + docker), move internal nginx config to docker.conf.j2 under the volume path, and rename host.conf.j2 to proxy.conf.j2 for the external vhost.
- web-app-magento: rename nginx.conf.j2 to docker.conf.j2 and update the runtime template task accordingly to make the intent (internal nginx) explicit.
- web-app-matrix: rename nginx.conf.j2 to synapse.conf.j2 and adjust the webserver task to use the new template name for the synapse vhost.
- web-app-bridgy-fed & web-app-flowise: pass domain and http_port explicitly when including sys-stk-front-proxy so the front stack has all required context.
- web-svc-cdn/file/html: replace direct sys-stk-front-base + sys-util-csp-cert + nginx.conf.j2 handling with sys-stk-front-proxy and proxy.conf.j2, relying on the shared front-stack for TLS/CSP/vHost wiring.
- web-svc-collabora: drop the direct nginx.conf.j2 vhost generation and rename it to proxy.conf.j2 so it is picked up by sys-stk-front-proxy like other services.
- web-opt-rdr-domains: rename redirect.domain.nginx.conf.j2 to redirect-domain.conf.j2 and adjust the task for clearer and more consistent naming.
Context: see ChatGPT refactor discussion on 2025-11-30 (proxy unification, Collabora/Nextcloud/CDN stacks, CSP/header handling): https://chatgpt.com/share/692c64ea-a488-800f-ad42-7f7692a3742f
