chore: ajouter les fichiers .env.example et extraire les secrets hardcodés

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

gitea/docker-compose.yml

@@ -8,7 +8,7 @@ services:
     environment:
       POSTGRES_DB: gitea
       POSTGRES_USER: gitea
-      POSTGRES_PASSWORD: change_me
+      POSTGRES_PASSWORD: ${GITEA_POSTGRES_PASSWORD}
       TZ: Europe/Paris
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U $$POSTGRES_USER -d $$POSTGRES_DB"]
@@ -47,7 +47,7 @@ services:
       GITEA__database__HOST: db:5432
       GITEA__database__NAME: gitea
       GITEA__database__USER: gitea
-      GITEA__database__PASSWD: change_me
+      GITEA__database__PASSWD: ${GITEA_POSTGRES_PASSWORD}
 
       TZ: Europe/Paris
     volumes:
@@ -88,7 +88,7 @@ services:
       - gitea
     environment:
       GITEA_INSTANCE_URL: http://gitea:3000
-      GITEA_RUNNER_REGISTRATION_TOKEN: VBV30irSexdiyvHyzlX0HAmb1iV3XGiDm37raumU
+      GITEA_RUNNER_REGISTRATION_TOKEN: ${GITEA_RUNNER_REGISTRATION_TOKEN}
       GITEA_RUNNER_NAME: docker-runner
       GITEA_RUNNER_LABELS: ubuntu-latest:host
       CONFIG_FILE: /config.yaml