feat: pipeline CI + Docker pour déploiement sur sonic

- Dockerfile multi-stage (node:20 build + nginx:alpine serve)
- nginx.conf SPA avec try_files et gzip
- docker-compose.yml avec labels Registrator/Fabio (SERVICE_80_CHECK_TCP)
- .woodpecker.yml : validate, security-check, build-image, SBOM, write-env,
  test-env, deploy (stop→acme→up), test-deploy, healthcheck
- .gitignore : ajout .env et /.reports/

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

docker-compose.yml

@@ -0,0 +1,18 @@
+name: ${COMPOSE_PROJECT_NAME:-syoul-g1flux-main}
+
+services:
+  app:
+    image: g1flux:latest
+    container_name: ${COMPOSE_PROJECT_NAME:-syoul-g1flux-main}-app
+    restart: always
+    labels:
+      - SERVICE_80_NAME=${COMPOSE_PROJECT_NAME:-syoul-g1flux-main}-app-80
+      - SERVICE_80_TAGS=urlprefix-${APP_DOMAIN}/*
+      - SERVICE_80_CHECK_TCP=true
+      - LETSENCRYPT_HOST=${APP_DOMAIN}
+    networks:
+      - sonic
+
+networks:
+  sonic:
+    external: true