Docs-as-code: full deploy configs, compose stacks, and DR guide

- Add root README and docs/ (architecture, hosts, disaster-recovery, operations)
- Add compose/ for superset, forgejo, lam, cadvisor; unified deploy compose
- Add scripts/deploy (deploy-atc-docker01.sh, container inventory export)
- Add inventory/containers-atc-docker01.json snapshot
- Add config READMEs for kafka and airflow; .env.example; expand .gitignore
- Sync atclab helper scripts; update homepage/superset compose with env support

deploy/docker-compose.homepage.yml

@@ -12,7 +12,7 @@ services:
       - ../config/homepage:/app/config
       - /var/run/docker.sock:/var/run/docker.sock:ro
     environment:
-      HOMEPAGE_ALLOWED_HOSTS: "*"
+      HOMEPAGE_ALLOWED_HOSTS: ${HOMEPAGE_ALLOWED_HOSTS:-atc-docker01.dell-atc.lan,localhost}
 
   rss-proxy:
     build: ../rss-proxy