Give a connector node an icon that is not a code icon

A device read over a proprietary protocol was showing the fallback used
for a function node. A connector's type cannot be in the built-in icon
map — that is the point of it being a connector — so they share a plug.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011LF61rxW1FG5YCD2J9YqjY

frontend/src/components/Flow/FlowEditor.tsx

@@ -303,6 +303,18 @@ function FlowEditorInner({
     [nodeTypeInfo],
   )
 
+  // Which types came from an installed connector rather than the engine. They
+  // cannot be in the icon map, so they share one.
+  const pluginTypes = useMemo(
+    () =>
+      new Set(
+        (nodeTypeInfo ?? [])
+          .filter((info) => info.plugin)
+          .map((info) => info.type),
+      ),
+    [nodeTypeInfo],
+  )
+
   const issuesByNode = useMemo(() => {
     const map = new Map<string, string[]>()
     for (const issue of issues) {
@@ -328,11 +340,20 @@ function FlowEditorInner({
             flow: flowName,
             typeLabel:
               typeLabels.get(definition?.type ?? "") ?? definition?.type ?? "",
+            isPlugin: pluginTypes.has(definition?.type ?? ""),
             issueText: nodeIssues.join("\n"),
           } satisfies FlowNodeData,
         }
       }),
-    [canvasNodes, definitions, flowName, issuesByNode, selectedId, typeLabels],
+    [
+      canvasNodes,
+      definitions,
+      flowName,
+      issuesByNode,
+      pluginTypes,
+      selectedId,
+      typeLabels,
+    ],
   )
 
   // A cheap fingerprint of the wiring: it changes when a name does, but not