Document full application landscape and collect Docker configs

- Add docs/landscape.md and docker-inventory.md with Mermaid architecture
- Add config/docker per host (db02, lake01, kafka01) and objectscale/elastic refs
- Add live architecture page at icons/docs/architecture.html
- Homepage OPS tab: Lakehouse Architecture group with diagram link
- Add scripts/collect/collect-fleet-config.sh to refresh configs from fleet

config/docker/atc-kafka01/docker-compose.yml

@@ -0,0 +1,14 @@
+# Kafka UI — atc-kafka01 (10.0.21.36)
+# Kafka broker runs natively on :9092 (see /opt/kafka on host).
+version: "3.9"
+
+services:
+  kafka-ui:
+    image: provectuslabs/kafka-ui:latest
+    container_name: kafka-ui
+    restart: unless-stopped
+    ports:
+      - "9000:8080"
+    environment:
+      KAFKA_CLUSTERS_0_NAME: atc-kafka
+      KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS: localhost:9092