Let a node's failure outlive the run that followed it

A node's error cleared the moment it ran again, so a failure that genuinely
fired an alert could leave no trace on the canvas by the time anyone looked.
The engine records it now — on the node's status, so it survives a reload and
every client agrees — and reading the traceback is what clears it. The seam is
the event bus, which is where every failing path already meets: a queued live
run, an explicit run, a preview, and a single triggered node all publish
`node_error`, while the controller's own observer would have seen only one of
them.

That was half the confusion. The other half: clicking a failed neuron on Home
often landed on a flow where everything looked fine. Nodes merge into one
neuron by instance key — every InfluxDB node pointing at the same bucket is one
neuron — and the click went to whichever flow contributed a member first, not
the one that failed. It now goes to the failing member and selects it, and the
canvas marks a failing node rather than leaving it to the dot alone.

The inject node emitted one payload to every port it declared, whatever their
types, so an inject on a bool port carrying the text "true" raised at publish
time. Each port gets its own field now, typed and parsed by that port's dtype,
and remembers what it last sent. A port that is renamed carries its value with
it; one that is removed takes its value with it. An inject written before this
keeps emitting exactly what it did.

The derived-cron chip also appeared on the delay node, where `interval` is a
rate limit and a schedule derived from it means nothing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uq8mtNb97A7praJLyeEYgs

frontend/src/routes/_canvas/flows/$flowName.tsx

@@ -4,8 +4,16 @@ import { Suspense } from "react"
 import { FlowEditor } from "@/components/Flow/FlowEditor"
 import { Skeleton } from "@/components/ui/skeleton"
 
+type Search = { node?: string }
+
 export const Route = createFileRoute("/_canvas/flows/$flowName")({
   component: FlowRoute,
+  // Which node to arrive on. A search param rather than a hash so the brain
+  // graph's click-through — and any link out of an alert — is a whole address
+  // someone can send.
+  validateSearch: (search: Record<string, unknown>): Search => ({
+    node: typeof search.node === "string" ? search.node : undefined,
+  }),
   head: ({ params }) => ({
     meta: [{ title: `${params.flowName} - Fluksio` }],
   }),
@@ -21,10 +29,11 @@ function Loading() {
 
 function FlowRoute() {
   const { flowName } = Route.useParams()
+  const { node } = Route.useSearch()
 
   return (
     <Suspense fallback={<Loading />}>
-      <FlowEditor flowName={flowName} />
+      <FlowEditor flowName={flowName} focus={node} />
     </Suspense>
   )
 }

frontend/src/routes/_layout/index.tsx

@@ -17,11 +17,11 @@ import { Switch } from "@/components/ui/switch"
 import useCustomToast from "@/hooks/useCustomToast"
 
 export const Route = createFileRoute("/_layout/")({
-  component: Dashboard,
+  component: Home,
   head: () => ({
     meta: [
       {
-        title: "Dashboard - Fluksio",
+        title: "Home - Fluksio",
       },
     ],
   }),
@@ -50,7 +50,7 @@ function FlowRow({ flow }: { flow: FlowSummary }) {
   return (
     <div
       className="flex items-center gap-3 border-b border-border px-5 py-3 last:border-b-0"
-      data-testid="dashboard-flow-row"
+      data-testid="home-flow-row"
     >
       <Link
         to="/flows/$flowName"
@@ -100,7 +100,7 @@ function FlowRow({ flow }: { flow: FlowSummary }) {
  * it has been doing. The brain and the health screens compose in here rather
  * than living at routes of their own.
  */
-function Dashboard() {
+function Home() {
   // The health block's window: one choice, read by the tiles, the flow table,
   // the charts and the lists under them.
   const [range, setRange] = useState(DEFAULT_RANGE)