externalize github copilot code

packages/opencode/src/auth/copilot.ts

@@ -0,0 +1,20 @@
+import { Global } from "../global"
+import { lazy } from "../util/lazy"
+import path from "path"
+
+export const AuthCopilot = lazy(async () => {
+  const file = Bun.file(path.join(Global.Path.cache, "copilot.ts"))
+  const response = fetch(
+    "https://raw.githubusercontent.com/sst/opencode-github-copilot/refs/heads/main/auth.ts",
+  )
+    .then((x) => Bun.write(file, x))
+    .catch(() => {})
+
+  if (!file.exists()) {
+    const worked = await response
+    if (!worked) return
+  }
+  const result = await import(file.name!).catch(() => {})
+  if (!result) return
+  return result.AuthCopilot
+})