feat(provider): add GitHub Enterprise support for Copilot (#2522)

Co-authored-by: Jon-Mikkel Korsvik <48263282+jkorsvik@users.noreply.github.com>
Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Aiden Cline <aidenpcline@gmail.com>

packages/opencode/src/auth/index.ts

@@ -10,6 +10,7 @@ export namespace Auth {
       refresh: z.string(),
       access: z.string(),
       expires: z.number(),
+      enterpriseUrl: z.string().optional(),
     })
     .meta({ ref: "OAuth" })