Add api/cdc_consumer.py: aiokafka background consumer subscribes to the CDC
topics (postgres_sales/mysql_hr/mongodb_supplychain + cassandra/neo4j), parses
Debezium before/after envelopes, keeps a ring buffer and publishes each change
live as type=cdc_change. Endpoints /api/changes, /api/changes/stats, /status.
Adds an Analytics sub-tab to the Hadoop view with live KPIs and revenue
breakdowns (by year/region/category/channel) queried from Trino over
iceberg.hadoop.historical_sales, plus a query-engine comparison panel. Trino
latency is measured live; Impala and Hive are shown as clearly-labelled
representative figures (those engines are not deployed). New cached endpoints
/api/hadoop/analytics and /api/hadoop/engines.
Clicking agents opens a dedicated terminal panel; topology PostgreSQL/Trino nodes open SQL workbench with ten demo queries and Postgres vs Trino benchmark.