Vendor opencode source for docker build

opencode/packages/app/src/utils/base64.ts

@@ -0,0 +1,10 @@
+import { base64Decode } from "@opencode-ai/util/encode"
+
+export function decode64(value: string | undefined) {
+  if (value === undefined) return
+  try {
+    return base64Decode(value)
+  } catch {
+    return
+  }
+}