perf: add bans.user_id index, Redis cache layer, rate-limit improvements, radio contest/giveaway columns, and tests

- Add DB index on bans.user_id to speed up per-request ban lookups (migration 0008)
- Replace in-process rate limiter with Redis-backed implementation with in-memory fallback
- Add Redis caching layer for site settings with TTL invalidation (migration 0009)
- Add rate limiting to resetPassword to prevent token brute-force attacks
- Update all rateLimit callers to await the now-async function
- Flesh out RadioContests and RadioGiveaways models with title, description, prize, date, and winner columns
- Update radio contest/giveaway pages to display new fields
- Add tests for rate limiter (4 tests) and password-reset actions (3 tests)
- Add REDIS_URL environment variable (optional, falls back to in-memory)

src/app/radio/contests/[id]/page.tsx

@@ -1,5 +1,6 @@
 import Link from "next/link";
 import { notFound } from "next/navigation";
+import { getTranslations } from "next-intl/server";
 import { ContentCard } from "@/components/public/ui";
 import { prisma } from "@/lib/prisma";
 
@@ -15,9 +16,8 @@ export default async function RadioContestDetailPage({
   params: Promise<{ id: string }>;
 }) {
   const { id } = await params;
+  const t = await getTranslations("pages.radioContests");
 
-  // Route param is a string; RadioContests.id is a BigInt. Guard against a
-  // non-numeric id before constructing the BigInt (would otherwise throw).
   let contestId: bigint;
   try {
     contestId = BigInt(id);
@@ -31,7 +31,7 @@ export default async function RadioContestDetailPage({
 
   if (!contest) notFound();
 
-  const contestIdStr = contest.id.toString();
+  const active = contest.isActive ? "Active" : "Ended";
 
   return (
     <main style={{ display: "grid", gap: "1.5rem" }}>
@@ -39,9 +39,29 @@ export default async function RadioContestDetailPage({
         <Link href="/radio/contests">← Back to contests</Link>
       </p>
 
-      <ContentCard icon="🎉" title={`Contest #${contestIdStr}`} subtitle="Radio contest details">
-        <table>
+      <ContentCard icon="🎉" title={contest.title || `Contest #${contest.id}`} subtitle={active}>
+        <table style={{ width: "100%" }}>
           <tbody>
+            {contest.description ? (
+              <tr>
+                <th style={{ verticalAlign: "top", width: 120 }}>Description</th>
+                <td>{contest.description}</td>
+              </tr>
+            ) : null}
+            {contest.prize ? (
+              <tr>
+                <th>Prize</th>
+                <td>{contest.prize}</td>
+              </tr>
+            ) : null}
+            <tr>
+              <th>Period</th>
+              <td>
+                {contest.startDate ? formatDate(contest.startDate) : "—"}
+                {" — "}
+                {contest.endDate ? formatDate(contest.endDate) : "ongoing"}
+              </td>
+            </tr>
             <tr>
               <th>Created</th>
               <td>{formatDate(contest.createdAt) || <span className="muted">—</span>}</td>