feat: add Sablier v1.10.1 plugin for dynamic scaling

Added Sablier plugin and service for scale-to-zero capabilities:

**Traefik Plugin:**
- Added experimental.plugins.sablier configuration
- Plugin version: v1.10.1
- Module: github.com/acouvreur/sablier/plugins/traefik

**Sablier Service:**
- Created sablier/compose.yaml with Sablier server
- Uses Docker provider for container management
- Mounts Docker socket for container control
- Connected to falcon_network

**Configuration:**
- Added SABLIER_COMPOSE_PROJECT_NAME to arty.yml
- Added SABLIER_VERSION to arty.yml
- Included sablier stack in compose.yaml

**Usage:**
Services can now use Sablier middleware to automatically
scale to zero when idle and start on demand when accessed.

Example middleware configuration:
```yaml
http:
  middlewares:
    my-sablier:
      plugin:
        sablier:
          sablierUrl: http://sablier_app:10000
          names: service-name
          sessionDuration: 1m
```

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

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

compose.yaml

@@ -9,6 +9,7 @@ include:
   - stash/compose.yaml
   - links/compose.yaml
   - umami/compose.yaml
+  - sablier/compose.yaml
   - proxy/compose.yaml
   - watch/compose.yaml