chore(ats): adding Dockerfile and docker-compose

[afidosiev]

Description

• Adding multi-stage Dockerfile that builds the contracts, SDK and the web app, serving the production bundle with Nginx
• Adding Nginx configuration for SPA routing
• Adding docker-compose.yml file with build args sourced from .env (required args + commented optional overrides)
• Adding .dockerignore
• Adding Docker steps to the web app README and full-setup guide

Type of change

• Bug fix 🐞
• New feature ✨
• Breaking change 💥
• Documentation update 📖
• Refactor 🔧

Testing

Node version:

• 20
• 22
• 24

Checklist

• Style Guidelines followed ✅
• Documentation Updated 📚
• Linters - No New Warnings ⚠️
• Local Tests Pass ✅
• Effective Tests Added ✔️
• No reduction of Coverage ✅

[hedera-eng-infrastructure]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

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