Rework the dashboards onto the flow canvas

One shell for both editors. Flows and dashboards each get a searchable
overview under the padded shell, their editors move to the full-bleed
canvas, and the floating chrome is shared: a title bar that only says
what you are looking at, and a bottom dock carrying everything else —
the flow bar's status, settings and Publish moved down there, the
add-flow button moved to the overview.

Dashboards gain the rest of M4's visualization work:

- widgets are picked by clicking them, with the header as the drag
  handle so a slider still slides and a switch still flips while
  editing; settings moved into the flows' SidePanel
- react-grid-layout for drag and edge-resize, so the stored x/y finally
  mean something; a dashboard nobody arranged is shelf-packed once
- a per-dashboard grid size, so a panel can be matched to its screen
- the chart widget, drawn with uPlot: several messages on one axis, fed
  from the stored history plus the live socket tail, coloured from the
  new --chart-1..5 ramp
- /view/{name}: the URL a wall panel is pointed at — no sidebar, no
  footer, no editing, and no editor code, since routes are split
- a widget wired to a payload type it cannot carry, or wired to nothing
  at all, carries the same red dot a failing node does; the picker
  records the type it bound and WidgetDef refuses a mismatch on save

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H7LwYgJfpkbLCTeiAf8U4A

frontend/src/routes/view.$name.tsx

@@ -0,0 +1,37 @@
+import { useQuery } from "@tanstack/react-query"
+import { createFileRoute, redirect } from "@tanstack/react-router"
+
+import type { Dashboard } from "@/components/Dashboard/DashboardView"
+import { DashboardView } from "@/components/Dashboard/DashboardView"
+import { dashboardQueryOptions } from "@/components/Dashboard/queries"
+import { useFlowSocket } from "@/components/Flow/useFlowSocket"
+import { isLoggedIn } from "@/hooks/useAuth"
+
+/**
+ * What a wall panel is pointed at.
+ *
+ * Deliberately outside both shells: no sidebar, no footer, no editing, and no
+ * column cap — the widgets are the whole page. Route splitting means a panel
+ * never downloads the editor or the grid library either.
+ */
+export const Route = createFileRoute("/view/$name")({
+  component: PanelView,
+  beforeLoad: async () => {
+    if (!isLoggedIn()) {
+      throw redirect({ to: "/login" })
+    }
+  },
+  head: ({ params }) => ({ meta: [{ title: `${params.name} - Fluksio` }] }),
+})
+
+function PanelView() {
+  const { name } = Route.useParams()
+  useFlowSocket()
+  const { data: dashboard } = useQuery(dashboardQueryOptions(name))
+
+  return (
+    <main className="dot-canvas min-h-svh w-full overflow-y-auto p-4">
+      {dashboard ? <DashboardView dashboard={dashboard as Dashboard} /> : null}
+    </main>
+  )
+}