Advisory issues read as advice rather than failure

`ADVISORY_ISSUES` moves next to `ValidationIssue` in pipeline.py, and the
model derives an `advisory` flag from its own code, so the distinction the
engine already made ships to the client instead of being re-guessed there.

The dock keeps its summary in `--destructive` only when a real fault is
among the issues and paints an advisory row `--muted-foreground`; the
canvas leaves advisories off a node's dot and border entirely, since node
status has three colours and no warning tier.

biome checks the generated `openapi.json`, which nothing formats since the
SDK script dropped its format pass — ignore it like the other generated
files.

frontend/src/components/Flow/FlowDock.tsx

@@ -110,6 +110,10 @@ export function FlowDock({
 }) {
   const { fitView } = useReactFlow()
   const connected = useLiveConnection()
+  // The engine marks the issues it does not count against a flow. They are
+  // still worth saying, so they stay in the list — but in the muted tone, and
+  // without turning the summary red, since nothing here is actually broken.
+  const faults = issues.filter((issue) => !issue.advisory)
 
   return (
     <motion.div
@@ -175,7 +179,12 @@ export function FlowDock({
               <Button
                 variant="ghost"
                 size="sm"
-                className="h-11 gap-1.5 text-destructive md:h-8"
+                className={cn(
+                  "h-11 gap-1.5 md:h-8",
+                  faults.length > 0
+                    ? "text-destructive"
+                    : "text-muted-foreground",
+                )}
                 data-testid="validation-summary"
               >
                 <AlertCircle className="size-4" />
@@ -191,7 +200,10 @@ export function FlowDock({
                   <li key={`${issue.code}-${issue.node}-${issue.message_name}`}>
                     <button
                       type="button"
-                      className="w-full rounded-sm px-2 py-1.5 text-left text-sm transition-colors hover:bg-accent/50 disabled:cursor-default disabled:hover:bg-transparent"
+                      className={cn(
+                        "w-full rounded-sm px-2 py-1.5 text-left text-sm transition-colors hover:bg-accent/50 disabled:cursor-default disabled:hover:bg-transparent",
+                        issue.advisory && "text-muted-foreground",
+                      )}
                       onClick={() => issue.node && onFocusNode(issue.node)}
                       disabled={!issue.node}
                     >

frontend/src/components/Flow/FlowEditor.tsx

@@ -336,7 +336,10 @@ function FlowEditorInner({
   const issuesByNode = useMemo(() => {
     const map = new Map<string, string[]>()
     for (const issue of issues) {
-      if (!issue.node) continue
+      // A node's dot and border are its status channel, and status has no
+      // warning tier — an advisory is not a fault, so it says its piece in the
+      // dock rather than painting the node red.
+      if (!issue.node || issue.advisory) continue
       const list = map.get(issue.node) ?? []
       list.push(issue.message)
       map.set(issue.node, list)