perf(gamification,dashboard,insights): cut achievements cold rebuilds and lazy-load three charts

Achievements: the bucket was 60 s hard-TTL while the app-wide unlock
notifier polls every 2 minutes, so every poll landed on an expired
entry and fired a cold ~400 ms rebuild in the foreground. Add a
10-minute stale-while-revalidate window and read the route through
cachedSwr; the route already persists pendingUnlocks outside the cached
factory, so a stale serve never skips an unlock write.

Achievements builder: the vitals array ran through several full-array
passes, each re-deriving a Berlin day-key (and hour) per row via
Intl.DateTimeFormat. Compute each row's day-key once and thread the
parallel array into the green-day, weekly-consistency, engagement, and
hidden passes; the hidden pass reuses a single precomputed hour array.
Results are byte-identical to the per-row derivation (parity test added).

dashboard/summary: read through cachedSwr so the iOS-polled endpoint
serves its existing 1 h stale window instead of re-paying the cold
rebuild every 60 s on the plain cached path.

Charts: route the three recharts consumers that bypassed the shared
next/dynamic boundary (lab biomarker chart, sleep stage stacked bar,
recommendation rationale charts) through dynamic imports with matching
loading skeletons, taking recharts off the first-load JS for
/labs/[id], /insights/sleep, and the insights recommendations surface.

src/app/api/dashboard/summary/route.ts

@@ -55,7 +55,7 @@ import { CUMULATIVE_HK_TYPES } from "@/lib/measurements/apple-health-mapping";
 import { getServerTranslator } from "@/lib/i18n/server-translator";
 import { defaultLocale, locales, type Locale } from "@/lib/i18n/config";
 import { userDayKey, DEFAULT_TIMEZONE } from "@/lib/tz/resolver";
-import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
+import { cachedSwr, caches, type ServerCache } from "@/lib/cache/server-cache";
 import { buildMedsTodayBlock } from "@/lib/dashboard/meds-today";
 import {
   summarizeSleepNights,
@@ -328,12 +328,23 @@ export const GET = apiHandler(async () => {
   // it).
   const userTz = user.timezone ?? DEFAULT_TIMEZONE;
 
-  // v1.4.38 W-F — wrap the whole response in the 60 s analytics LRU.
+  // v1.4.38 W-F — wrap the whole response in the analytics LRU.
   // Subsequent iOS polls inside the TTL hit memory; measurement /
   // mood / medication writes invalidate the user-bucket via the
   // existing `invalidateUserMeasurements` + the v1.4.38-extended
   // `invalidateUserMedications` hooks.
-  const body = await cached(
+  //
+  // v1.18.11 (W5 perf) — read via `cachedSwr`. The `analytics` bucket
+  // already provisions a 1 h `staleTtlMs` window, but this endpoint read
+  // through plain `cached` and so ignored it: the iOS client polls every
+  // 60 s, and a plain read past the 60 s fresh TTL re-paid the full cold
+  // rebuild on every poll. `cachedSwr` serves the prior body instantly
+  // inside the stale window and warms one background recompute instead.
+  // Writes still mark/evict the bucket, so a user's own action is
+  // reflected on the very next read — the window only bounds wall-clock
+  // drift (the same self-correcting `nextDueOverdue`/tally drift the
+  // snapshot read already tolerates).
+  const body = await cachedSwr(
     caches.analytics as ServerCache<
       Awaited<ReturnType<typeof buildDashboardSummary>>
     >,

src/app/api/gamification/achievements/route.ts

@@ -3,7 +3,7 @@ import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { requireModuleEnabled, resolveModuleMap } from "@/lib/modules/gate";
 import { annotate } from "@/lib/logging/context";
 import { apiSuccess } from "@/lib/api-response";
-import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
+import { cachedSwr, caches, type ServerCache } from "@/lib/cache/server-cache";
 import {
   buildAchievementsResult,
   type AchievementsResult,
@@ -72,7 +72,13 @@ export const GET = apiHandler(async (request: NextRequest) => {
   // a toggle change is reflected on the next read.
   const moduleMap = await resolveModuleMap(user.id);
 
-  const result = await cached(
+  // v1.18.11 (W5 perf) — read via `cachedSwr`. The bucket carries a
+  // 10-minute stale window; the app-wide `AchievementUnlockNotifier` polls
+  // every 2 minutes, so a hard-TTL read always missed and re-paid the cold
+  // build. SWR serves the prior payload instantly and warms one background
+  // recompute. Persistence of `pendingUnlocks` stays OUTSIDE this read (see
+  // below), so a stale-served body never skips an unlock write.
+  const result = await cachedSwr(
     caches.achievements as ServerCache<AchievementsResult>,
     user.id,
     () => buildAchievementsResult(user, moduleMap),