feat(admin): default Vercel routing to 50% and clarify UI text (#2786)

Co-authored-by: kiloconnect[bot] <240665456+kiloconnect[bot]@users.noreply.github.com>

Author: kilo-code-bot[bot]

apps/web/src/app/admin/gateway/RoutingContent.tsx

@@ -70,9 +70,10 @@ export function RoutingContent() {
         <CardHeader>
           <CardTitle>Vercel Routing Percentage</CardTitle>
           <CardDescription>
-            Control the percentage of traffic routed to the Vercel AI Gateway (vs OpenRouter). Leave
-            empty to use the default ({DEFAULT_VERCEL_PERCENTAGE}%). Stored in Redis for
-            sub-millisecond reads on the hot path.
+            For models available on the Vercel AI Gateway, controls the percentage of traffic routed
+            to Vercel (vs OpenRouter). Models not available on Vercel always go to OpenRouter, so
+            overall traffic may still be skewed towards OpenRouter. Leave empty to use the default (
+            {DEFAULT_VERCEL_PERCENTAGE}%).
           </CardDescription>
         </CardHeader>
         <CardContent className="flex flex-col gap-4">

apps/web/src/lib/ai-gateway/gateway-config.ts

@@ -1,6 +1,6 @@
 import * as z from 'zod';
 
-export const DEFAULT_VERCEL_PERCENTAGE = 10;
+export const DEFAULT_VERCEL_PERCENTAGE = 50;
 
 const vercelRoutingPercentage = z.number().int().min(0).max(100);