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

config/airflow/README.md

@@ -0,0 +1,14 @@
+# Airflow
+
+| Bestand | Beschrijving |
+|---------|--------------|
+| `airflow.cfg` | Referentie-configuratie (deploy naar Airflow home op lake01) |
+| `generate_data_dag.py` | DAG voor demo data-generatie |
+
+## URL
+
+http://atc-lake01.dell-atc.lan:8080/ (of `10.0.21.55:8080` volgens netwerk)
+
+## Deploy
+
+Kopieer `generate_data_dag.py` naar de Airflow `dags/` folder op de lake-host en herstart de scheduler/webserver.