feat: add on-demand sitemap revalidation webhook

.env.example

@@ -87,3 +87,13 @@ STEAMGRIDDB_API_KEY="your_steamgriddb_api_key_here"
 # -----------------------------------------------------------------------------
 # Discord webhook URL for contact/report submissions
 DISCORD_WEBHOOK_URL=""
+
+# -----------------------------------------------------------------------------
+# SITEMAP
+# -----------------------------------------------------------------------------
+# Secret token for on-demand sitemap revalidation (generate with: openssl rand -base64 32)
+# Leave empty to disable the revalidation endpoint
+REVALIDATE_SECRET=""
+
+# ISR revalidation interval in seconds for sitemap.xml (default: 3600 = 1 hour)
+SITEMAP_REVALIDATE_SECONDS=""

app/api/revalidate-sitemap/route.ts

@@ -0,0 +1,54 @@
+import { revalidatePath } from "next/cache"
+import { NextRequest, NextResponse } from "next/server"
+
+/**
+ * On-demand sitemap revalidation webhook.
+ *
+ * What this endpoint does:
+ *   Revalidates the `/sitemap.xml` path so Next.js regenerates the sitemap
+ *   at the edge instead of waiting for the next ISR interval.
+ *
+ * When to call it:
+ *   - After adding, updating, or removing games
+ *   - After adding, updating, or removing hardware
+ *   - After any bulk import or migration that affects public-facing URLs
+ *
+ * How to call it:
+ *   ```bash
+ *   curl -X POST https://<your-domain>/api/revalidate-sitemap \
+ *     -H "Authorization: Bearer $REVALIDATE_SECRET"
+ *   ```
+ *
+ * @see https://nextjs.org/docs/app/building-your-application/caching#on-demand-revalidation
+ */
+export async function POST(request: NextRequest): Promise<NextResponse> {
+  const authHeader = request.headers.get("authorization")
+  const secret = process.env.REVALIDATE_SECRET
+
+  if (!secret) {
+    return NextResponse.json(
+      { error: "Revalidation not configured. Set REVALIDATE_SECRET env var." },
+      { status: 503 },
+    )
+  }
+
+  const token = authHeader?.replace("Bearer ", "")
+  if (token !== secret) {
+    return NextResponse.json({ error: "Invalid secret" }, { status: 401 })
+  }
+
+  try {
+    revalidatePath("/sitemap.xml")
+    return NextResponse.json({
+      revalidated: true,
+      path: "/sitemap.xml",
+      now: Date.now(),
+    })
+  } catch (error) {
+    console.error("[Revalidate Sitemap] Failed:", error)
+    return NextResponse.json(
+      { error: "Revalidation failed" },
+      { status: 500 },
+    )
+  }
+}