feat: usage quota visualization in AI settings

No user-facing view of AI-call/recipe/storage usage existed — only an
admin-only per-user panel. Adds the same numbers, with progress bars
against the user's actual tier limits (read fresh from the DB, not
the cached session), to Settings > AI.

v0.40.0

apps/web/app/(app)/settings/ai/page.tsx

@@ -1,10 +1,12 @@
 import type { Metadata } from "next";
 import { headers } from "next/headers";
 import { auth } from "@/lib/auth/server";
-import { db, userAiKeys, userModelPrefs, eq } from "@epicure/db";
+import { db, userAiKeys, userModelPrefs, users, tierDefinitions, userUsage, eq, and } from "@epicure/db";
+import { UNLIMITED } from "@/lib/tiers";
 import { ByokManager } from "@/components/settings/byok-manager";
 import { ModelPrefsForm } from "@/components/settings/model-prefs-form";
-import { getMessages } from "@/lib/i18n/server";
+import { UsageQuotaSection } from "@/components/settings/usage-quota-section";
+import { getMessages, formatMessage } from "@/lib/i18n/server";
 
 export const metadata: Metadata = {};
 
@@ -13,7 +15,9 @@ export default async function AiSettingsPage() {
   if (!session) return null;
   const m = getMessages((session.user as { locale?: string }).locale);
 
-  const [aiKeys, modelPrefs] = await Promise.all([
+  const currentMonth = new Date().toISOString().slice(0, 7);
+
+  const [aiKeys, modelPrefs, dbUser] = await Promise.all([
     db.query.userAiKeys.findMany({
       where: eq(userAiKeys.userId, session.user.id),
       columns: { provider: true },
@@ -21,10 +25,52 @@ export default async function AiSettingsPage() {
     db.query.userModelPrefs.findFirst({
       where: eq(userModelPrefs.userId, session.user.id),
     }),
+    // Tier comes from the DB, not the (up to 5-minute-stale) session cookie
+    // cache, so a just-changed tier's limits show up immediately here.
+    db.query.users.findFirst({ where: eq(users.id, session.user.id), columns: { tier: true } }),
   ]);
 
+  const [tierDef, usage] = await Promise.all([
+    db.query.tierDefinitions.findFirst({ where: eq(tierDefinitions.tier, dbUser?.tier ?? "free") }),
+    db.query.userUsage.findFirst({ where: and(eq(userUsage.userId, session.user.id), eq(userUsage.month, currentMonth)) }),
+  ]);
+
+  const asLimit = (n: number | undefined) => (n === undefined || n === UNLIMITED ? null : n);
+
+  const usageMetrics = [
+    {
+      label: m.settings.usage.aiCalls,
+      used: usage?.aiCallsUsed ?? 0,
+      limit: asLimit(tierDef?.aiCallsPerMonth),
+      unlimitedLabel: m.settings.usage.unlimited,
+    },
+    {
+      label: m.settings.usage.recipes,
+      used: usage?.recipeCount ?? 0,
+      limit: asLimit(tierDef?.maxRecipes),
+      unlimitedLabel: m.settings.usage.unlimited,
+    },
+    {
+      label: m.settings.usage.storage,
+      used: usage?.storageUsedMb ?? 0,
+      limit: asLimit(tierDef?.storageMb),
+      unit: " MB",
+      unlimitedLabel: m.settings.usage.unlimited,
+    },
+  ];
+
   return (
     <div className="space-y-8">
+      <section className="rounded-xl border p-6 space-y-4">
+        <div>
+          <h2 className="font-semibold text-lg">{m.settings.usage.title}</h2>
+          <p className="text-sm text-muted-foreground mt-1">
+            {formatMessage(m.settings.usage.description, { month: currentMonth })}
+          </p>
+        </div>
+        <UsageQuotaSection metrics={usageMetrics} />
+      </section>
+
       <section className="rounded-xl border p-6 space-y-4">
         <div>
           <h2 className="font-semibold text-lg">{m.settings.byok.title}</h2>