feat(docs): add Coolify deployment guide and integrate into setup documentation

feat(scripts): add environment verification scripts for deployment checks

docs/SETUP.md

@@ -453,6 +453,38 @@ To allow the Gitea Actions runner (or your local machine) to deploy to the remot
      unset DOCKER_HOST
      ```
 
+### Coolify Deployment
+
+Coolify is an open-source, self-hostable PaaS (Heroku/Netlify/Vercel
+alternative) that can deploy the Linear Void stack through a web UI with
+automatic HTTPS and one-click redeploys. It replaces the deployment
+orchestration layer (the Gitea CD `DOCKER_HOST` flow) while leaving Cloudflare
+DNS, R2 media, and cache rules unchanged.
+
+To deploy via Coolify:
+
+1. **Install Coolify** on a dedicated server:
+
+   ```bash
+   curl -fsSL https://cdn.coollabs.io/coolify/install.sh | bash
+   ```
+
+2. **Add the target server** in the dashboard via SSH (or use Localhost if
+   Coolify runs on the same machine as the stack).
+3. **Create a Docker Compose resource** pointing at either the Git repository
+   (`docker-compose.prod.yml`) or the compose file contents directly.
+4. **Configure environment variables** in Coolify's secret store (the values
+   normally held in `.env`), keeping internal URLs on compose hostnames
+   (`redis`, `db`).
+5. **Map persistent storage** for `data/` mounts and the `redis-data` /
+   `postgres-data` named volumes so data survives redeploys.
+6. **Assign a domain** to the nginx service so Coolify's Traefik proxy
+   terminates TLS for `linearvoid.tv`, while `media.linearvoid.tv` continues to
+   serve HLS from Cloudflare R2.
+
+For the full walkthrough, environment-variable table, verification steps, and
+cutover notes, see [COOLIFY.md](./COOLIFY.md).
+
 ### Production Setup Guide
 
 1. **Prepare the target host**: