fix(sdk): add gpt-5.2-codex, gpt-5.3-codex, and gpt-5.2 to model-variant detection

[enyst]

Summary

Fixes #2233 - Add gpt-5.3-codex and gpt-5.2-codex to model-variant detection to avoid gpt-5 fallback.

Previously, gpt-5.3-codex and gpt-5.2-codex were incorrectly classified as gpt-5 instead of gpt-5-codex due to substring-based matching in _MODEL_VARIANT_PATTERNS. This caused codex models to inherit non-codex prompt behavior, leading to malformed pseudo-tool output and early run termination.

Changes

• Added gpt-5.2-codex and gpt-5.3-codex to the gpt-5-codex variant patterns
• Added gpt-5.2 to the gpt-5 variant patterns

Checklist

• If the PR is changing/adding functionality, are there tests to reflect this? Yes - Added tests/sdk/utils/test_model_prompt_spec.py with tests for gpt-5 variant detection
• If there is an example, have you run the example to make sure that it works? N/A
• If there are instructions on how to run the code, have you followed the instructions and made sure that it works? Yes - Verified with manual tests and pytest
• If the feature is significant enough to require documentation, is there a PR open on the OpenHands/docs repository with the same branch name? N/A
• Is the github CI passing? To be verified

---

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:python3.12-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:3298927-python

Run

docker run -it --rm \
  -p 8000:8000 \
  --name agent-server-3298927-python \
  ghcr.io/openhands/agent-server:3298927-python

All tags pushed for this build

ghcr.io/openhands/agent-server:3298927-golang-amd64
ghcr.io/openhands/agent-server:3298927-golang_tag_1.21-bookworm-amd64
ghcr.io/openhands/agent-server:3298927-golang-arm64
ghcr.io/openhands/agent-server:3298927-golang_tag_1.21-bookworm-arm64
ghcr.io/openhands/agent-server:3298927-java-amd64
ghcr.io/openhands/agent-server:3298927-eclipse-temurin_tag_17-jdk-amd64
ghcr.io/openhands/agent-server:3298927-java-arm64
ghcr.io/openhands/agent-server:3298927-eclipse-temurin_tag_17-jdk-arm64
ghcr.io/openhands/agent-server:3298927-python-amd64
ghcr.io/openhands/agent-server:3298927-nikolaik_s_python-nodejs_tag_python3.12-nodejs22-amd64
ghcr.io/openhands/agent-server:3298927-python-arm64
ghcr.io/openhands/agent-server:3298927-nikolaik_s_python-nodejs_tag_python3.12-nodejs22-arm64
ghcr.io/openhands/agent-server:3298927-golang
ghcr.io/openhands/agent-server:3298927-java
ghcr.io/openhands/agent-server:3298927-python

About Multi-Architecture Support

• Each variant tag (e.g., 3298927-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., 3298927-python-amd64) are also available if needed

[github-actions]

API breakage checks (Griffe)

Result: Passed

Action log

[github-actions]

Agent server REST API breakage checks (OpenAPI)

Result: Passed

Action log

[all-hands-bot]

Taste Rating: 🟢 Good taste - Clean fix for a real bug. The ordered tuple approach elegantly solves the substring matching problem. LGTM.

[github-actions]

Coverage Report •

File	Stmts	Miss	Cover	Missing
openhands-sdk/openhands/sdk/llm/utils
model_prompt_spec.py	38	2	94%	55, 75
TOTAL	19000	5681	70%