feat(ai-gateway): gate Vercel routing for exclusive models with vercel-routing flag (#3005)

* feat(ai-gateway): add vercel-routing flag to gate Vercel routing for exclusive models

Kilo-exclusive models are now only eligible for random Vercel routing
when they carry the new 'vercel-routing' flag or are not exclusive at
all. This prevents surprises such as StepFun Flash (an exclusive model
on OpenRouter) suddenly being routed through Vercel if Vercel begins
hosting it. The flag is set only on the currently disabled MiniMax M2.5
free model for now.

* refactor(ai-gateway): drop redundant openrouter check and inline defaultProvider

---------

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

Author: kilo-code-bot[bot]

apps/web/src/lib/ai-gateway/providers/get-provider.ts

@@ -175,19 +175,20 @@ export async function getProvider(
   }
 
   const kiloExclusiveModel = kiloExclusiveModels.find(m => m.public_id === requestedModel);
-  const defaultProvider =
-    Object.values(PROVIDERS).find(p => p.id === kiloExclusiveModel?.gateway) ??
-    PROVIDERS.OPENROUTER;
+  const eligibleForVercelRouting =
+    !kiloExclusiveModel || kiloExclusiveModel.flags.includes('vercel-routing');
 
   if (
-    defaultProvider.id === 'openrouter' &&
+    eligibleForVercelRouting &&
     (await shouldRouteToVercel(requestedModel, request, taskId || user.id))
   ) {
     return { provider: PROVIDERS.VERCEL_AI_GATEWAY, userByok: null, bypassAccessCheck: false };
   }
 
   return {
-    provider: defaultProvider,
+    provider:
+      Object.values(PROVIDERS).find(p => p.id === kiloExclusiveModel?.gateway) ??
+      PROVIDERS.OPENROUTER,
     userByok: null,
     bypassAccessCheck: false,
   };

apps/web/src/lib/ai-gateway/providers/kilo-exclusive-model.ts

@@ -5,7 +5,7 @@ import {
 } from '@/lib/ai-gateway/providers/openrouter/inference-provider-id';
 import type { ProviderId } from '@/lib/ai-gateway/providers/types';
 
-export type KiloExclusiveModelFlag = 'reasoning' | 'vision' | 'stealth';
+export type KiloExclusiveModelFlag = 'reasoning' | 'vision' | 'stealth' | 'vercel-routing';
 
 export type Usage = {
   uncachedInputTokens: number;

apps/web/src/lib/ai-gateway/providers/minimax.ts

@@ -8,7 +8,7 @@ export const minimax_m25_free_model: KiloExclusiveModel = {
   context_length: 204800,
   max_completion_tokens: 131072,
   status: 'disabled',
-  flags: ['reasoning'],
+  flags: ['reasoning', 'vercel-routing'],
   gateway: 'openrouter',
   internal_id: 'minimax/minimax-m2.5',
   pricing: null,