core: fix GitHub Copilot Enterprise authentication failing with sdk.chat undefined error

packages/opencode/src/provider/provider.ts

@@ -515,7 +515,7 @@ export namespace Provider {
         continue
       }
 
-      if (providerID === "github-copilot") {
+      if (providerID === "github-copilot" || providerID === "github-copilot-enterprise") {
         provider.info.npm = "@ai-sdk/github-copilot"
       }