chore: migrate remaining legacy license headers to The OpenSandbox Authors

Overview

Following the donation of OpenSandbox to AAIF, PR #1878 updated code generation scripts, templates, and newly generated code to attribute copyright to The OpenSandbox Authors.

Remaining Scope

The remaining ~1600+ hand-written files across the repository still carry the legacy Alibaba Group Holding Ltd. header:

• sdks/sandbox/python/src/opensandbox (~98 files)
• Other SDKs (Kotlin, C#, Java, Go handwritten files, ~170+ files)
• server/ (~350+ files)
• components/ (execd, egress, ingress, nodeagent, ~300+ files)
• kubernetes/ (controller, manifests, etc.)
• cli/

Plan

1. Migrate components/packages incrementally in focused follow-up PRs per package/module.
2. Once the codebase is fully migrated, drop the legacy Alibaba Group Holding Ltd. fallback branch in scripts/verify-license.sh and scripts/add-license.sh so verification strictly enforces The OpenSandbox Authors.