feat(dataflow): live Data Flow graph API + PII catalog

api/dataflow.py: node-link landscape (generators->sources->CDC/Kafka->sinks,
HDFS->Iceberg, sources->curated_masked) with live overlays (movement run state,
CDC volume, Trino counts) and PII overlay. api/pii_catalog.py: column PII
classification via Trino information_schema (OM-ready). Endpoints /api/dataflow,
/api/dataflow/{id}/run, /api/pii.

api/main.py

@@ -45,6 +45,8 @@ from sql_console import router as sql_router
 from agent_ops import router as agent_ops_router, agent_dml_loop, etl_agent_loop
 from cdc_consumer import router as cdc_router, cdc_consumer_loop
 from movements import router as movements_router
+from dataflow import router as dataflow_router
+from pii_catalog import router as pii_router
 from ssh_terminal import ssh_session
 from node_registry import NODE_IDS, NODE_AGENT, NODE_REGISTRY, is_node_id
 from node_ops import build_node_detail, probe_node, run_node_probe_task
@@ -737,6 +739,8 @@ app.include_router(sql_router)
 app.include_router(agent_ops_router)
 app.include_router(cdc_router)
 app.include_router(movements_router)
+app.include_router(dataflow_router)
+app.include_router(pii_router)
 app.add_middleware(
     CORSMiddleware,
     allow_origins=["*"],