feat: move restic (backrest) to core stack

- Add backrest service to core/compose.yaml with CORE_RESTIC_ prefix
- Update arty.yml with CORE_RESTIC_* environment variables
- Remove restic from compose.yaml includes
- Backrest now part of core infrastructure stack

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

arty.yml

@@ -19,6 +19,12 @@ envs:
     CORE_REDIS_PORT: 6379
     CORE_REDIS_IMAGE: redis:7-alpine
     CORE_POSTGRES_IMAGE: postgres:16-alpine
+    # Backrest (Restic)
+    CORE_RESTIC_TRAEFIK_ENABLED: true
+    CORE_RESTIC_IMAGE: garethgeorge/backrest:latest
+    CORE_RESTIC_TRAEFIK_HOST: restic.pivoine.art
+    CORE_RESTIC_HOSTNAME: falcon
+    CORE_RESTIC_BACKUP_PATH: /mnt/hidrive/users/valknar/Backup
     # Sexy
     SEXY_TRAEFIK_ENABLED: true
     SEXY_COMPOSE_PROJECT_NAME: sexy
@@ -79,13 +85,6 @@ envs:
     STASH_TRAEFIK_HOST: stash.pivoine.art
     STASH_PORT: 8334
     STASH_CANARY: true
-    # Restic
-    RESTIC_TRAEFIK_ENABLED: true
-    RESTIC_COMPOSE_PROJECT_NAME: restic
-    RESTIC_IMAGE: garethgeorge/backrest:latest
-    RESTIC_TRAEFIK_HOST: restic.pivoine.art
-    RESTIC_HOSTNAME: falcon
-    RESTIC_BACKUP_PATH: /mnt/hidrive/users/valknar/Backup
     # Jellyfin
     JELLY_TRAEFIK_ENABLED: true
     JELLY_COMPOSE_PROJECT_NAME: jelly