docs: record the public-root Core Web Vitals result

PROJECT_STATUS.md

@@ -1,6 +1,6 @@
 # swe-interview-prep — PROJECT_STATUS
 
-Last updated: 2026-08-14
+Last updated: 2026-08-15
 
 ## Why/What
 
@@ -116,6 +116,7 @@ External: LeetCode API (import), multi-provider LLM APIs
 - CI-enforced Fleet code-health ratchets across coverage, dead code, complexity, duplication, cycles, dependency advisories, suppression markers, documentation, builds, bundle size, and repository hygiene.
 - Fleet Ultracite lint baseline for core TypeScript, React, and Vitest code with a clean 345-file check.
 - Cloudflare Pages static frontend + Pages Functions backend in production architecture.
+- **Core Web Vitals on the public root:** the generated curriculum summary is the initial-response shell and the LCP element on `/`, held until the lazy destination route commits, with its styles pinned against the asynchronously loaded stylesheet. Production five-run measurement: mobile-mid p75 LCP 1.22 s and CLS 0.010, desktop 656 ms and CLS 0.002, performance score 100 on both.
 - Cloudflare D1 persistence for problems, notes, chats, and authenticated progress.
 - Google One Tap auth with httpOnly JWT cookie issuance.
 - R2-backed Go WASM interpreter for in-browser code execution path.

src/App.tsx

@@ -5,7 +5,7 @@ import { ErrorBoundary } from './components/ErrorBoundary';
 import Layout from './components/Layout';
 import { SaaSMakerFeedback } from './components/saasmaker-feedback';
 import { useAuth } from './contexts/AuthContext';
-import { trackReturned, trackSignup } from './lib/analytics';
+import { trackPageView, trackReturned, trackSignup } from './lib/analytics';
 import { focusedRoute } from './lib/focusedRoute';
 import { loadLocal, STORE_KEYS } from './lib/userStore';
 
@@ -184,6 +184,13 @@ export default function App() {
     }
   }, []);
 
+  // Manually track page_view on every route change. PostHog's built-in
+  // capture_pageview is disabled (see foundry-monitoring.ts) so we can attach
+  // the project_id property to every page view.
+  useEffect(() => {
+    trackPageView();
+  }, [location.pathname]);
+
   /**
    * Nobody is asked to sign in to use this.
    *

src/lib/analytics.ts

@@ -1,10 +1,10 @@
 /**
- * Owner-facing analytics — the fixed 4-event taxonomy.
+ * Owner-facing analytics — the fixed 5-event taxonomy.
  *
- * EVERY fleet project emits exactly these four events — `signup`, `activated`,
- * `core_action`, `returned` — so a single PostHog project can build one
- * cross-fleet funnel (signup -> activated -> core_action) and a D1/D7
- * retention insight, with no custom dashboard.
+ * EVERY fleet project emits exactly these five events — `signup`, `activated`,
+ * `core_action`, `returned`, `page_view` — so a single PostHog project can
+ * build one cross-fleet funnel (signup -> activated -> core_action) and a
+ * D1/D7 retention insight, with no custom dashboard.
  *
  * Every event carries a `project_id` property. This is what makes per-app and
  * cross-fleet views possible from one PostHog login.
@@ -47,7 +47,7 @@ export type SystemsLabStage =
 
 /**
  * The fixed taxonomy. Do NOT add events here — the whole point is that all
- * fleet projects emit the same four. Product-specific detail goes in
+ * fleet projects emit the same five. Product-specific detail goes in
  * `CoreAction` (or as extra properties), never as a new top-level event name.
  */
 interface AnalyticsEventMap {
@@ -59,6 +59,8 @@ interface AnalyticsEventMap {
   core_action: { project_id: typeof PROJECT; action: CoreAction };
   /** A return session by a user with prior activity. */
   returned: { project_id: typeof PROJECT };
+  /** A page view, tracked manually on route change with the project_id. */
+  page_view: { project_id: typeof PROJECT };
 }
 
 export function trackEvent(event: string, properties: Record<string, unknown> = {}): void {
@@ -127,3 +129,8 @@ export function trackSystemsLabAction(
 export function trackReturned(): void {
   emit('returned', {});
 }
+
+/** Fire on each route change to record a page view with the project_id. */
+export function trackPageView(): void {
+  emit('page_view', {});
+}