feat: add admin sitemap regeneration endpoint and cron task

lib/api/sitemap-regenerate.ts

@@ -0,0 +1,24 @@
+import { Elysia } from "elysia"
+import { requireAdmin } from "@/lib/auth/guard"
+import { generateSitemaps } from "@/lib/sitemap/generate-static"
+
+export const sitemapRegenerateRoutes = new Elysia({ prefix: "/sitemap" })
+
+  .post(
+    "/regenerate",
+    async ({ request, set }) => {
+      const guard = await requireAdmin(request.headers)
+      if (!guard.ok) {
+        set.status = guard.status
+        return { error: guard.error }
+      }
+
+      try {
+        await generateSitemaps()
+        return { success: true, message: "Sitemap regenerated successfully" }
+      } catch (err) {
+        set.status = 500
+        return { error: "Failed to regenerate sitemap", details: err instanceof Error ? err.message : String(err) }
+      }
+    },
+  )