refactor: remove diagramNodeId indirection, use processorId directly

Agent now uses Camel processorId as RouteNode.id, eliminating the
nodeId mapping layer. Drop diagram_node_id column (V6 migration),
remove from ProcessorRecord/ProcessorNode/IngestionService/DetailService,
add /processor-routes endpoint for processorId→routeId lookup,
simplify frontend diagram-mapping and ExchangeDetail overlays,
replace N diagram fetches in AppConfigPage with single hook.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/ExchangeDetail/ExchangeDetail.tsx

@@ -172,19 +172,10 @@ export default function ExchangeDetail() {
   const { routeFlows, flowIndexMap } = useMemo(() => {
     let nodes: RouteNode[]
     if (diagram?.nodes) {
-      // Flatten processors to build diagramNodeId → processorId lookup
-      const flatProcs: Array<{ diagramNodeId?: string; processorId?: string }> = []
-      function flattenProcs(list: any[]) {
-        for (const n of list) { flatProcs.push(n); if (n.children) flattenProcs(n.children) }
-      }
-      flattenProcs(procList)
-      const pidLookup = new Map(flatProcs
-        .filter(p => p.diagramNodeId && p.processorId)
-        .map(p => [p.diagramNodeId!, p.processorId!]))
-
+      // node.id is the processorId (Camel nodeId), so lookup is direct
       nodes = mapDiagramToRouteNodes(diagram.nodes, procList).map((node, i) => ({
         ...node,
-        badges: badgesFor(pidLookup.get(diagram.nodes[i]?.id ?? '') ?? diagram.nodes[i]?.id ?? ''),
+        badges: badgesFor(diagram.nodes[i]?.id ?? ''),
       }))
     } else {
       // Fallback: build from processor list
@@ -211,22 +202,11 @@ export default function ExchangeDetail() {
     return ids
   }, [procList])
 
-  // ProcessorId lookup: diagram node index → processorId
+  // ProcessorId lookup: diagram node index → processorId (node.id IS processorId)
   const flowProcessorIds: string[] = useMemo(() => {
     if (!diagram?.nodes) return processorIds
-    const flatProcs: Array<{ diagramNodeId?: string; processorId?: string }> = []
-    function flatten(nodes: any[]) {
-      for (const n of nodes) {
-        flatProcs.push(n)
-        if (n.children) flatten(n.children)
-      }
-    }
-    flatten(procList)
-    const lookup = new Map(flatProcs
-      .filter(p => p.diagramNodeId && p.processorId)
-      .map(p => [p.diagramNodeId!, p.processorId!]))
-    return diagram.nodes.map(node => lookup.get(node.id ?? '') ?? node.id ?? '')
-  }, [diagram, procList, processorIds])
+    return diagram.nodes.map(node => node.id ?? '')
+  }, [diagram, processorIds])
 
   // Map flow display index → processor tree index (for snapshot API)
   const flowToTreeIndex = useMemo(() =>