fix+upstream: hooks-order crash, ConfirmDialog/PageHeader/skeletons, styled error boundary

Hoists hooks above early return (render-time Navigate); ports finance's
ConfirmDialog/PageHeader/loading/states + APC error-copy mapper; removes
window.confirm, dead appbar search, and seeded fake notifications; wires toasts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/routes/home.tsx

@@ -2,13 +2,8 @@ import { ArrowRight, Sparkles, Boxes, Activity, BookOpen } from "lucide-react"
 import { Link } from "react-router"
 
 import { AppShell } from "~/components/layout/app-shell"
-import {
-  Card,
-  CardContent,
-  CardDescription,
-  CardHeader,
-  CardTitle,
-} from "~/components/ui/card"
+import { PageHeader } from "~/components/layout/page-header"
+import { Card, CardDescription, CardHeader, CardTitle } from "~/components/ui/card"
 import { pageTitle } from "~/lib/page-meta"
 
 export const meta = () => pageTitle("Overview")
@@ -44,19 +39,19 @@ const tiles = [
 export default function HomeRoute() {
   return (
     <AppShell title="Overview">
-      <Card>
-        <CardHeader>
-          <CardTitle>Welcome</CardTitle>
-          <CardDescription>
+      <PageHeader
+        title="Welcome"
+        description={
+          <>
             A hybrid traditional + AI-first scaffold. Use the rail to navigate;
             the Assistant can drive the UI on your behalf — try{" "}
             <kbd className="rounded border bg-muted px-1.5 py-0.5 font-mono text-xs">
               ⌘⇧P
             </kbd>{" "}
             for the script runner.
-          </CardDescription>
-        </CardHeader>
-      </Card>
+          </>
+        }
+      />
 
       <div className="grid gap-4 md:grid-cols-2">
         {tiles.map((t) => {