fix(security): harden cron and API route authentication

- public-holidays cron: replace fail-open inline auth check with verifyCronSecret
  (was open to unauthenticated access when CRON_SECRET unset)
- /api/perf: replace timing-unsafe string comparison with verifyCronSecret
- /api/health: strip baseUrl and latency fields from response to avoid
  leaking infrastructure details (NEXTAUTH_URL config, internal timings)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/app/api/cron/public-holidays/route.ts

@@ -2,6 +2,7 @@ import { NextResponse } from "next/server";
 import { prisma } from "@capakraken/db";
 import { autoImportPublicHolidays } from "@capakraken/api";
 import { logger } from "@capakraken/api/lib/logger";
+import { verifyCronSecret } from "~/lib/cron-auth.js";
 
 export const dynamic = "force-dynamic";
 export const runtime = "nodejs";
@@ -16,17 +17,11 @@ export const runtime = "nodejs";
  * Query params:
  *   - year (optional): defaults to next year
  *
- * Optionally protected with CRON_SECRET environment variable.
- * When set, requests must include `Authorization: Bearer <secret>`.
+ * Protected with CRON_SECRET via `Authorization: Bearer <secret>` header.
  */
 export async function GET(request: Request) {
-  const cronSecret = process.env["CRON_SECRET"];
-  if (cronSecret) {
-    const auth = request.headers.get("authorization");
-    if (auth !== `Bearer ${cronSecret}`) {
-      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
-    }
-  }
+  const deny = verifyCronSecret(request);
+  if (deny) return deny;
 
   const { searchParams } = new URL(request.url);
   const yearParam = searchParams.get("year");

apps/web/src/app/api/health/route.ts

@@ -38,18 +38,11 @@ async function checkRedis(): Promise<"ok" | "error"> {
   });
 }
 
-function checkBaseUrl(): { configured: boolean; isLocalhost: boolean } {
-  const raw = process.env["NEXTAUTH_URL"]?.trim();
-  if (!raw) return { configured: false, isLocalhost: false };
-  return { configured: true, isLocalhost: raw.startsWith("http://localhost") };
-}
-
 export async function GET() {
   const [db, redis] = await Promise.all([checkDb(), checkRedis()]);
-  const baseUrl = checkBaseUrl();
   const ok = db === "ok" && redis === "ok";
   return NextResponse.json(
-    { status: ok ? "ok" : "degraded", db, redis, baseUrl, timestamp: new Date().toISOString() },
+    { status: ok ? "ok" : "degraded", db, redis },
     { status: ok ? 200 : 503 },
   );
 }

apps/web/src/app/api/perf/route.ts

@@ -1,5 +1,6 @@
 import { NextResponse } from "next/server";
 import { eventBus } from "@capakraken/api/sse";
+import { verifyCronSecret } from "~/lib/cron-auth.js";
 
 export const dynamic = "force-dynamic";
 export const runtime = "nodejs";
@@ -13,16 +14,8 @@ export const runtime = "nodejs";
  * Returns Node.js memory usage, process uptime, and SSE connection count.
  */
 export function GET(request: Request) {
-  const cronSecret = process.env["CRON_SECRET"];
-
-  if (!cronSecret) {
-    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
-  }
-
-  const headerToken = request.headers.get("authorization")?.replace("Bearer ", "");
-  if (headerToken !== cronSecret) {
-    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
-  }
+  const deny = verifyCronSecret(request);
+  if (deny) return deny;
 
   const mem = process.memoryUsage();