perf(insights): defer below-fold mother-page blocks behind next/dynamic + bundle config hygiene

Lighthouse v1.4.33 flagged ~463 KiB of unused JS on first /insights
paint plus ~211 KiB of bundled JS as unminified. Two coordinated
moves close the gap without touching the Coach panel internals or
the dashboard tree.

next.config.ts
- `compiler.removeConsole` with `exclude: ["error", "warn"]` strips
  the chart-wiring + Coach SSE breadcrumb literals from the prod
  bundle. Error + warn paths still flow through to GlitchTip.
- `headers()` advertises `Permissions-Policy: unload=()` so Chromium
  admits the page to the back/forward cache when navigating away. We
  carry no `beforeunload` / `unload` listeners in-tree so the hint is
  honest.

src/app/insights/page.tsx
- `<DailyBriefing>`, `<CorrelationRow>`, `<TrendsRow>` move behind
  `next/dynamic({ ssr: false, loading: <Skeleton /> })`. All three
  paint below the hero on every viewport and were eagerly imported
  before. Each loader skeleton matches the dimensions of the resolved
  block so layout doesn't shift.
- `<HeroStrip>` stays an eager import — the greeting + health-score
  badge are the visible-first-paint surface.

next.config.ts

@@ -4,6 +4,39 @@ import bundleAnalyzer from "@next/bundle-analyzer";
 const nextConfig: NextConfig = {
   output: "standalone",
   poweredByHeader: false,
+  // v1.4.33 IW2 — strip `console.*` calls from the production bundle
+  // (keep `console.error` + `console.warn` so the GlitchTip reporter
+  // and prod-side debug rails still surface). The Lighthouse audit
+  // flagged ~211 KiB of bundled JS as "unminified" — Turbopack already
+  // mangles + minifies the chunks, but the in-tree `console.log`
+  // breadcrumbs from the chart wiring + Coach SSE handlers carried
+  // hundreds of preserved string literals through to the client. The
+  // SWC compiler drops the calls + their literal-only arguments
+  // entirely in production.
+  compiler: {
+    removeConsole:
+      process.env.NODE_ENV === "production"
+        ? { exclude: ["error", "warn"] }
+        : false,
+  },
+  // v1.4.33 IW2 — bfcache hygiene. `Permissions-Policy: unload=()`
+  // tells the browser the page does not need the `unload` event,
+  // which Chromium uses as a hint to admit the page to the
+  // back/forward cache on navigation away. Pair with the absence of
+  // any `beforeunload` / `unload` listener in our own code so the
+  // bfcache restore path stays clear. The other CSP-style security
+  // headers already live on the response via the standalone runtime;
+  // we add only the bfcache hint here.
+  async headers() {
+    return [
+      {
+        source: "/:path*",
+        headers: [
+          { key: "Permissions-Policy", value: "unload=()" },
+        ],
+      },
+    ];
+  },
   serverExternalPackages: [
     "@prisma/client",
     "pg-boss",

src/app/insights/page.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useQuery } from "@tanstack/react-query";
+import dynamic from "next/dynamic";
 import Link from "next/link";
 import { Loader2, TrendingUp } from "lucide-react";
 
@@ -11,15 +12,60 @@ import { useTranslations } from "@/lib/i18n/context";
 import { Button } from "@/components/ui/button";
 import { EmptyState } from "@/components/ui/empty-state";
 import { HeroStrip } from "@/components/insights/hero-strip";
-import { DailyBriefing } from "@/components/insights/daily-briefing";
-import { TrendsRow } from "@/components/insights/trends-row";
-import { CorrelationRow } from "@/components/insights/correlation-row";
 import { useInsightsAdvisorQuery } from "@/components/insights/use-insights-advisor";
 import { useCoachLaunch } from "@/lib/insights/coach-launch-context";
 import { useAnalyticsQuery } from "@/lib/queries/use-analytics-query";
 import type { CorrelationResult } from "@/lib/insights/correlations";
 import type { DataSummary } from "@/lib/analytics/trends";
 
+/**
+ * v1.4.33 IW2 — defer the three below-the-fold mother-page blocks
+ * behind `next/dynamic`. `<HeroStrip>` (the only above-the-fold piece)
+ * stays an eager import so the initial paint shows the greeting and
+ * health-score badge without a flash; the briefing, correlation row
+ * and trends row each carry their own icon-set + chart wiring (a chart
+ * card alone weighs in at the lucide tree-shake limit) and used to
+ * land on every Insights cold mount. Loader skeletons match the
+ * existing fallback so the layout doesn't shift while the chunks
+ * resolve.
+ */
+const DailyBriefing = dynamic(
+  () =>
+    import("@/components/insights/daily-briefing").then((mod) => ({
+      default: mod.DailyBriefing,
+    })),
+  {
+    ssr: false,
+    loading: () => (
+      <div className="bg-card border-border h-48 animate-pulse rounded-xl border" />
+    ),
+  },
+);
+const CorrelationRow = dynamic(
+  () =>
+    import("@/components/insights/correlation-row").then((mod) => ({
+      default: mod.CorrelationRow,
+    })),
+  {
+    ssr: false,
+    loading: () => (
+      <div className="bg-card border-border h-32 animate-pulse rounded-xl border" />
+    ),
+  },
+);
+const TrendsRow = dynamic(
+  () =>
+    import("@/components/insights/trends-row").then((mod) => ({
+      default: mod.TrendsRow,
+    })),
+  {
+    ssr: false,
+    loading: () => (
+      <div className="bg-card border-border h-64 animate-pulse rounded-xl border" />
+    ),
+  },
+);
+
 /**
  * v1.4.25 W4d — Insights mother page.
  *