fix(docs): correct OpenCode Zen description in code comment (#9998)

* fix(docs): correct OpenCode Zen description in code comment

OpenCode Zen is a pay-as-you-go token-based API, not a $200/month
subscription. The subscription tiers ($20/$100/$200) are OpenCode Black,
a separate product.

This fixes the misleading comment that conflated Zen with Black.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: align OpenCode Zen billing copy (#9998) (thanks @therealZpoint-bot)

---------

Co-authored-by: Claude <claude@archibald.local>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/commands/auth-choice.apply.api-providers.ts

@@ -752,7 +752,7 @@ export async function applyAuthChoiceApiProviders(
         [
           "OpenCode Zen provides access to Claude, GPT, Gemini, and more models.",
           "Get your API key at: https://opencode.ai/auth",
-          "Requires an active OpenCode Zen subscription.",
+          "OpenCode Zen bills per request. Check your OpenCode dashboard for details.",
         ].join("\n"),
         "OpenCode Zen",
       );