feat(web): tracking page — weight entries with sparkline + history (PRD §5.2)

New /tracking route in the editorial language:
- "CAPITOLO VI / Pesata e misure." masthead
- 7/5 split: form left, STORICO right

Form (left, "NUOVA RILEVAZIONE"):
- Date + weight required, with the latest weight pre-filled to encourage
  consistency between weeks
- Optional misure: girovita / fianchi / coscia / braccio (cm), grouped under
  a "MISURE (CM) — OPZIONALI" eyebrow
- Subjective indicators 1–10: energia / sonno / fame
- Italic "Registrato." (oliva) confirmation after a successful POST
- Server action calls POST /me/weight-entries through API_URL with the
  user's session cookie; sparkline + history revalidate via
  revalidatePath('/tracking')

History (right, "STORICO"):
- Inline SVG sparkline of the user's weight series with a terracotta dot
  marking the latest reading; ink-soft date axis labels under the line
- Two big mono stats: "PESO ATTUALE" and "VARIAZIONE" (oliva when negative,
  pomodoro when positive, ink at zero)
- Newest 8 entries listed with hairline rules between rows
- Italian italic empty-state copy when no entries exist yet

Home gains a third NavItem ("Tracking — Pesata & misure").

Verified manually with a fresh user signup → disclaimer → profile → tracking:
sparkline / "PESO ATTUALE 76.0 kg" / "VARIAZIONE 0.0 kg" / list row "29 apr 76.0 kg".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/app/[locale]/tracking/page.tsx

@@ -0,0 +1,66 @@
+import { prisma } from '@ketopath/db';
+import { redirect } from 'next/navigation';
+import { useTranslations } from 'next-intl';
+import { setRequestLocale } from 'next-intl/server';
+
+import { Masthead } from '@/components/masthead';
+import { getServerSession } from '@/lib/auth';
+
+import { fetchWeightEntries } from './actions';
+import { WeightEntryForm } from './weight-entry-form';
+import { WeightHistory } from './weight-history';
+
+export default async function TrackingPage({ params: { locale } }: { params: { locale: string } }) {
+  setRequestLocale(locale);
+  const session = await getServerSession();
+  if (!session?.user) redirect('/sign-in');
+
+  const user = await prisma.user.findUnique({
+    where: { id: session.user.id },
+    select: { disclaimerAcceptedAt: true, profile: { select: { id: true } } },
+  });
+  if (!user?.disclaimerAcceptedAt) redirect('/welcome');
+  if (!user.profile) redirect('/profile');
+
+  const entries = await fetchWeightEntries();
+
+  return <TrackingPageContent entries={entries} />;
+}
+
+function TrackingPageContent({
+  entries,
+}: {
+  entries: Awaited<ReturnType<typeof fetchWeightEntries>>;
+}) {
+  const t = useTranslations('Tracking');
+  const latest = entries[0] ?? null;
+
+  return (
+    <div className="mx-auto min-h-screen max-w-5xl px-6 sm:px-10">
+      <Masthead issueLabel="N. 06 — Tracking" />
+      <main className="py-12 sm:py-16">
+        <p className="editorial-eyebrow animate-fade-up">Capitolo VI</p>
+        <h1 className="font-display text-display text-ink animate-fade-up mt-3 font-medium leading-[0.95] tracking-tight [animation-delay:120ms]">
+          {t('title')}
+          <span className="text-pomodoro">.</span>
+        </h1>
+        <p className="font-display text-ink-soft animate-fade-up mt-6 max-w-2xl text-xl italic leading-snug [animation-delay:240ms]">
+          {t('subtitle')}
+        </p>
+
+        <div className="rule animate-rule-in my-10 [animation-delay:360ms]" />
+
+        <div className="grid gap-12 md:grid-cols-12">
+          <section className="animate-fade-up [animation-delay:300ms] md:col-span-7">
+            <p className="editorial-eyebrow mb-6">{t('newEntry')}</p>
+            <WeightEntryForm latest={latest} />
+          </section>
+          <aside className="md:border-ink/15 animate-fade-up [animation-delay:420ms] md:col-span-5 md:border-l md:pl-10">
+            <p className="editorial-eyebrow mb-6">{t('history')}</p>
+            <WeightHistory entries={entries} />
+          </aside>
+        </div>
+      </main>
+    </div>
+  );
+}