Add minimal Fly.io deployment tooling

[johannesmutter]

The goal of this PR is to add a simple deployment system (in this case for Fly.io). It's designed for Svelte developers who ship client sites regularly and want deployment to be a solved problem, without having to study lengthy deployment docs per provider.

The deploy script that was the inspirations for this in system606 was ~2000 LOC (interactive wizards, 25+ env vars, complex abstractions). For editable-website something much simpler is more suitable, that devs can understand, customize, and trust.

Design principles

• Config as code — Secrets schema in deploy/config.js, values in gitignored .env.production
• Platform files in root — fly.toml and Dockerfile must live in root (Fly.io requirement, same for Vercel/ Cloudflare), so we ship templates and copy on init. Adding it directly to repo would pollute the root folder and assume everyone has the same deployment target.
• Validation before action — Check secrets and gitignore before any deploy
• Let the platform do its job — Don't reinvent fly.toml in JavaScript; region/VM config stays in platform files
• Beginner-friendly, expert-capable — Interactive prompts for first-timers, CLI flags for automation

What's included

deploy/
├── config.js              # Secrets schema (DB_PATH, ORIGIN). Svelte devs will adjust this file ✍️
├── deploy.js              # Main script (~200 lines). Most will not need to modify this.
└── templates/fly/
    ├── fly.toml           # Template with placeholders. 
    └── Dockerfile         # Simple Node.js container

scripts/
└── start.js               # Production entry with graceful shutdown

npm scripts:

• deploy:init — First-time setup (creates fly.toml, Dockerfile, .env.production.example)
• deploy — Validate secrets and deploy
• deploy:secrets — Sync secrets to Fly.io

Future extensibility

Adding Vercel support would mean:

1. Add deploy/templates/vercel/vercel.json
2. Add vercel adapter to deploy/deploy.js
3. Update deploy:init to ask which platform

The architecture supports this without major refactoring.

[vercel]

@johannesmutter is attempting to deploy a commit to the Michael Aufreiter's projects Team on Vercel.

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