OpenHands/software-agent-sdk: v1.28.0

What's Changed

• fix(sdk): keep OpenHands provider by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3548
• test(agent-server): add cross lease coverage by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3559
• fix(llm): don't emit explicit cache_control markers for Gemini by @VascoSch92 in https://github.com/OpenHands/software-agent-sdk/pull/3586
• test(sdk): pin shell parser node shapes by @Fieldnote-Echo in https://github.com/OpenHands/software-agent-sdk/pull/3590
• Harden workflow GitHub context handling by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3372
• feat: add client-defined tools (no-op tools via JSON spec) by @xingyaoww in https://github.com/OpenHands/software-agent-sdk/pull/3306
• fix(sdk): reject client tool name collisions by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3614
• feat(models): add claude-fable-5 model support by @juanmichelini in https://github.com/OpenHands/software-agent-sdk/pull/3592
• [codex] Count tokens with tokenizer chat templates by @neubig in https://github.com/OpenHands/software-agent-sdk/pull/3593
• [codex] Sanitize malformed tool call recovery by @neubig in https://github.com/OpenHands/software-agent-sdk/pull/3575
• Expose active LLM profile in settings API by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3552
• feat(terminal): reject Python/JSON literals passed as bash commands by @juanmichelini in https://github.com/OpenHands/software-agent-sdk/pull/3582
• feat(agent-server): add OpenAI chat completions gateway by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3545
• fix(sdk): Support ACP model switching for custom/unknown providers via set_config_option by @Hades32 in https://github.com/OpenHands/software-agent-sdk/pull/3556
• Consume cached View in prepare_llm_messages by @csmith49 in https://github.com/OpenHands/software-agent-sdk/pull/3328
• Skip PR description check for release PRs by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3639
• Extend workspace session cookie lifetime to effectively never expire by @rbren in https://github.com/OpenHands/software-agent-sdk/pull/3637
• feat(agent-server): harden OpenAI gateway client compatibility by @enyst in https://github.com/OpenHands/software-agent-sdk/pull/3626
• Wrap condenser LLM errors as NoCondensationAvailableException by @csmith49 in https://github.com/OpenHands/software-agent-sdk/pull/3647
• fix(llm): recognize claude-fable-5 as a reasoning model by @juanmichelini in https://github.com/OpenHands/software-agent-sdk/pull/3642
• Release v1.28.0 by @all-hands-bot in https://github.com/OpenHands/software-agent-sdk/pull/3638

Full Changelog: https://github.com/OpenHands/software-agent-sdk/compare/v1.27.1...v1.28.0