Add register + logout auth flows, and batch-5 resources

Auth (hand-built, uses the auth core):
- /register + register() action: validates, hashes with argon2id (hashPassword),
  creates an emulator-compatible users row (accountCreated/ipRegister/ipCurrent/
  look), redirect kept outside try so NEXT_REDIRECT propagates. Login/register
  cross-links; header shows Register (logged-out) and a Logout (signOut) button.

Batch 5 (parallel agents): /admin/rooms (+[id]) search+detail, /admin/vouchers
(CRUD), /admin/subscriptions (read), /admin/calendar (campaigns+rewards read),
/marketplace (public). Header + admin nav extended.

Verified: tsc exit 0, vitest 48/48, next build exit 0 (52 page routes).

src/app/admin/vouchers/page.tsx

@@ -0,0 +1,123 @@
+import { createVoucher, deleteVoucher } from "@/actions/admin-vouchers";
+import { prisma } from "@/lib/prisma";
+
+export const dynamic = "force-dynamic";
+
+type VoucherRow = {
+  id: bigint;
+  code: string;
+  amount: number;
+  maxUses: number;
+  useCount: number;
+  expiresAt: Date | null;
+  createdAt: Date | null;
+};
+
+function fmtDate(d: Date | null): string {
+  if (!d) return "—";
+  return d.toISOString().slice(0, 16).replace("T", " ");
+}
+
+export default async function AdminVouchers() {
+  const now = Date.now();
+
+  let vouchers: VoucherRow[] = [];
+  try {
+    vouchers = await prisma.websiteShopVouchers.findMany({
+      select: {
+        id: true,
+        code: true,
+        amount: true,
+        maxUses: true,
+        useCount: true,
+        expiresAt: true,
+        createdAt: true,
+      },
+      orderBy: { id: "desc" },
+      take: 200,
+    });
+  } catch {
+    vouchers = [];
+  }
+
+  return (
+    <main>
+      <h1>Shop Vouchers</h1>
+      <p className="muted">
+        Codes redeemable on the website shop for a balance top-up. Each user can
+        use a given voucher once, up to its max uses.
+      </p>
+
+      <form action={createVoucher} className="card" style={{ marginBottom: "1.5rem" }}>
+        <h3 style={{ marginTop: 0 }}>New voucher</h3>
+        <div className="grid cols-2" style={{ marginBottom: "0.75rem" }}>
+          <label style={{ display: "flex", flexDirection: "column", gap: "0.3rem" }}>
+            <span className="muted">Code</span>
+            <input name="code" placeholder="SUMMER2026" maxLength={255} required />
+          </label>
+          <label style={{ display: "flex", flexDirection: "column", gap: "0.3rem" }}>
+            <span className="muted">Amount (balance added)</span>
+            <input name="amount" type="number" min={1} placeholder="50" required />
+          </label>
+          <label style={{ display: "flex", flexDirection: "column", gap: "0.3rem" }}>
+            <span className="muted">Max uses</span>
+            <input name="maxUses" type="number" min={1} defaultValue={1} required />
+          </label>
+          <label style={{ display: "flex", flexDirection: "column", gap: "0.3rem" }}>
+            <span className="muted">Expires at (optional)</span>
+            <input name="expiresAt" type="datetime-local" />
+          </label>
+        </div>
+        <button type="submit" className="btn btn-primary">Create voucher</button>
+      </form>
+
+      <div className="card">
+        <table>
+          <thead>
+            <tr>
+              <th>Code</th>
+              <th>Amount</th>
+              <th>Uses</th>
+              <th>Expires</th>
+              <th>Created</th>
+              <th />
+            </tr>
+          </thead>
+          <tbody>
+            {vouchers.map((v) => {
+              const expired = v.expiresAt ? v.expiresAt.getTime() <= now : false;
+              const usedUp = v.maxUses > 0 && v.useCount >= v.maxUses;
+              return (
+                <tr key={v.id.toString()}>
+                  <td>
+                    <code>{v.code}</code>
+                    {expired ? (
+                      <span className="muted"> · expired</span>
+                    ) : usedUp ? (
+                      <span className="muted"> · used up</span>
+                    ) : null}
+                  </td>
+                  <td>{v.amount}</td>
+                  <td>
+                    {v.useCount} / {v.maxUses}
+                  </td>
+                  <td className="muted">{fmtDate(v.expiresAt)}</td>
+                  <td className="muted">{fmtDate(v.createdAt)}</td>
+                  <td>
+                    <form action={deleteVoucher}>
+                      <input type="hidden" name="id" value={v.id.toString()} />
+                      <button type="submit" className="btn btn-danger">
+                        Delete
+                      </button>
+                    </form>
+                  </td>
+                </tr>
+              );
+            })}
+          </tbody>
+        </table>
+        {vouchers.length === 0 ? <p className="muted">No vouchers yet.</p> : null}
+      </div>
+    </main>
+  );
+}