feat: add health check API endpoint

- Introduced a new GET endpoint for health checks.
- Returns the status, current timestamp, enabled providers, and rate limit information.
- Utilizes environment variables for rate limit configuration.

Author: kWAYTV

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

@@ -0,0 +1,13 @@
+import { env } from "@/env";
+import { providers } from "@/providers/registry";
+
+export function GET() {
+  const enabledProviders = providers.map((p) => p.name);
+
+  return Response.json({
+    status: "ok",
+    timestamp: new Date().toISOString(),
+    providers: enabledProviders,
+    rateLimit: !!(env.UPSTASH_REDIS_REST_URL && env.UPSTASH_REDIS_REST_TOKEN),
+  });
+}