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/client/schemas.gen.ts

@@ -423,6 +423,11 @@ export const DashboardDef_InputSchema = {
             title: 'Canvas Height',
             default: 1080
         },
+        icon: {
+            type: 'string',
+            title: 'Icon',
+            default: ''
+        },
         pages: {
             items: {
                 '$ref': '#/components/schemas/PageDef-Input'
@@ -479,6 +484,11 @@ export const DashboardDef_OutputSchema = {
             title: 'Canvas Height',
             default: 1080
         },
+        icon: {
+            type: 'string',
+            title: 'Icon',
+            default: ''
+        },
         pages: {
             items: {
                 '$ref': '#/components/schemas/PageDef-Output'
@@ -528,6 +538,11 @@ export const DashboardSummarySchema = {
             type: 'boolean',
             title: 'Has Draft',
             default: false
+        },
+        version: {
+            type: 'integer',
+            title: 'Version',
+            default: 1
         }
     },
     type: 'object',
@@ -1003,6 +1018,11 @@ export const FlowSummarySchema = {
             type: 'boolean',
             title: 'Quarantined',
             default: false
+        },
+        version: {
+            type: 'integer',
+            title: 'Version',
+            default: 1
         }
     },
     type: 'object',
@@ -1679,6 +1699,22 @@ export const NodeStatusPublicSchema = {
                 }
             ],
             title: 'Health Detail'
+        },
+        last_error: {
+            type: 'string',
+            title: 'Last Error',
+            default: ''
+        },
+        last_error_ts: {
+            anyOf: [
+                {
+                    type: 'number'
+                },
+                {
+                    type: 'null'
+                }
+            ],
+            title: 'Last Error Ts'
         }
     },
     type: 'object',