fix: language default, google OAuth cookie issue, add admin tier/usage controls

- ai-generate-dialog: useLocale() returns {locale,setLocale} object, not
  string — was stringifying whole object as default language value
- auth/server: add trustedOrigins so session cookie survives reverse-proxy
  deployments where BETTER_AUTH_URL differs from container's own view
- admin: add tier limit editor (/admin/tiers) and per-user usage reset
  button, both audit-logged

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/admin/layout.tsx

@@ -3,13 +3,14 @@ import { headers } from "next/headers";
 import { auth } from "@/lib/auth/server";
 import { db, users, eq } from "@epicure/db";
 import Link from "next/link";
-import { Shield, Users, BookOpen, Settings, BarChart3, ClipboardList, HardDrive, Bot, ArrowLeft } from "lucide-react";
+import { Shield, Users, BookOpen, Settings, BarChart3, ClipboardList, HardDrive, Bot, ArrowLeft, Gauge } from "lucide-react";
 import { cn } from "@/lib/utils";
 
 const adminNav = [
   { href: "/admin", label: "Overview", icon: BarChart3 },
   { href: "/admin/users", label: "Users", icon: Users },
   { href: "/admin/recipes", label: "Recipes", icon: BookOpen },
+  { href: "/admin/tiers", label: "Tier Limits", icon: Gauge },
   { href: "/admin/audit-logs", label: "Audit Logs", icon: ClipboardList },
   { href: "/admin/storage", label: "Storage", icon: HardDrive },
   { href: "/admin/ai-config", label: "AI Config", icon: Bot },

apps/web/app/admin/tiers/page.tsx

@@ -0,0 +1,24 @@
+import type { Metadata } from "next";
+import { db, tierDefinitions } from "@epicure/db";
+import { TierLimitsForm } from "@/components/admin/tier-limits-form";
+
+export const metadata: Metadata = { title: "Tier Limits – Admin" };
+
+export default async function AdminTiersPage() {
+  const tiers = await db.select().from(tierDefinitions);
+
+  return (
+    <div className="space-y-8">
+      <div>
+        <h1 className="text-2xl font-bold tracking-tight">Tier Limits</h1>
+        <p className="text-muted-foreground text-sm mt-1">
+          Change monthly quotas per tier. Takes effect immediately for all users on that tier.
+        </p>
+      </div>
+
+      {tiers.map((tierDefinition) => (
+        <TierLimitsForm key={tierDefinition.tier} tierDefinition={tierDefinition} />
+      ))}
+    </div>
+  );
+}

apps/web/app/admin/users/[id]/page.tsx

@@ -6,6 +6,7 @@ import { Badge } from "@/components/ui/badge";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { Separator } from "@/components/ui/separator";
 import { UserEditor } from "@/components/admin/user-editor";
+import { ResetUsageButton } from "@/components/admin/reset-usage-button";
 import Link from "next/link";
 import { ArrowLeft } from "lucide-react";
 
@@ -118,6 +119,9 @@ export default async function AdminUserDetailPage({ params }: PageProps) {
               <span className="text-muted-foreground">Storage Used</span>
               <span className="font-medium">{usage?.storageUsedMb ?? 0} MB</span>
             </div>
+            <div className="pt-2">
+              <ResetUsageButton userId={user.id} />
+            </div>
           </CardContent>
         </Card>
       </div>