fix(security): remove stray comment; narrow credentialType to literal union

Author: waleedlatif1

apps/sim/lib/a2a/utils.ts

@@ -90,7 +90,6 @@ export async function createA2AClient(agentUrl: string, apiKey?: string): Promis
       } else if (init.body instanceof ArrayBuffer) {
         body = new Uint8Array(init.body)
       } else {
-        // URLSearchParams, Blob, ReadableStream, FormData — read as text via Response
         const text = await new Response(init.body as BodyInit).text()
         if (text) body = text
       }

apps/sim/lib/auth/credential-access.ts

@@ -13,7 +13,7 @@ export interface CredentialAccessResult {
   credentialOwnerUserId?: string
   workspaceId?: string
   resolvedCredentialId?: string
-  credentialType?: string
+  credentialType?: 'oauth' | 'service_account'
 }
 
 /**