Enforce REST API deprecation runway in breakage checks

[enyst]

Summary

• enforce the REST API breakage check with the documented removal target instead of a MINOR bump comparison
• reject other in-place REST contract breakages until the 5-minor-release deprecation runway has elapsed
• add CI script tests covering scheduled removals and non-removal breaking changes

Closes #2463.

Checklist

• If the PR is changing/adding functionality, are there tests to reflect this?
• If there is an example, have you run the example to make sure that it works?
• If there are instructions on how to run the code, have you followed the instructions and made sure that it works?
• If the feature is significant enough to require documentation, is there a PR open on the OpenHands/docs repository with the same branch name?
• Is the github CI passing?

---

Agent Server images for this PR

• GHCR package: https://github.com/OpenHands/agent-sdk/pkgs/container/agent-server

Variants & Base Images

Variant	Architectures	Base Image	Docs / Tags
java	amd64, arm64	eclipse-temurin:17-jdk	Link
python	amd64, arm64	nikolaik/python-nodejs:python3.13-nodejs22	Link
golang	amd64, arm64	golang:1.21-bookworm	Link

Pull (multi-arch manifest)

# Each variant is a multi-arch manifest supporting both amd64 and arm64
docker pull ghcr.io/openhands/agent-server:79bffdf-python

Run

docker run -it --rm \
  -p 8000:8000 \
  --name agent-server-79bffdf-python \
  ghcr.io/openhands/agent-server:79bffdf-python

All tags pushed for this build

ghcr.io/openhands/agent-server:79bffdf-golang-amd64
ghcr.io/openhands/agent-server:79bffdf-golang_tag_1.21-bookworm-amd64
ghcr.io/openhands/agent-server:79bffdf-golang-arm64
ghcr.io/openhands/agent-server:79bffdf-golang_tag_1.21-bookworm-arm64
ghcr.io/openhands/agent-server:79bffdf-java-amd64
ghcr.io/openhands/agent-server:79bffdf-eclipse-temurin_tag_17-jdk-amd64
ghcr.io/openhands/agent-server:79bffdf-java-arm64
ghcr.io/openhands/agent-server:79bffdf-eclipse-temurin_tag_17-jdk-arm64
ghcr.io/openhands/agent-server:79bffdf-python-amd64
ghcr.io/openhands/agent-server:79bffdf-nikolaik_s_python-nodejs_tag_python3.13-nodejs22-amd64
ghcr.io/openhands/agent-server:79bffdf-python-arm64
ghcr.io/openhands/agent-server:79bffdf-nikolaik_s_python-nodejs_tag_python3.13-nodejs22-arm64
ghcr.io/openhands/agent-server:79bffdf-golang
ghcr.io/openhands/agent-server:79bffdf-java
ghcr.io/openhands/agent-server:79bffdf-python

About Multi-Architecture Support

• Each variant tag (e.g., 79bffdf-python) is a multi-arch manifest supporting both amd64 and arm64
• Docker automatically pulls the correct architecture for your platform
• Individual architecture tags (e.g., 79bffdf-python-amd64) are also available if needed

[github-actions]

Python API breakage checks — ✅ PASSED

Result: ✅ PASSED

Action log

[github-actions]

REST API breakage checks (OpenAPI) — ✅ PASSED

Result: ✅ PASSED

Action log

[github-actions]

Coverage Report •

File	Stmts	Miss	Cover	Missing
TOTAL	19950	8875	55%

report-only-changed-files is enabled. No files were changed during this commit :)

[all-hands-bot]

🟡 Acceptable - Solid engineering that solves a real problem. The core logic correctly enforces the documented 5-minor-release deprecation runway. A few minor suggestions for robustness below, but nothing blocking.