- Add `codex.orphan-delegation-compatibility` configuration option and mirror it to SDK configuration.
- Convert orphan Codex delegation outputs into standard user messages for requests with `X-Openai-Subagent: collab_spawn`.
- Integrate orphan delegation rewriting into OpenAI responses request handling pipeline.
Closes: #5401
Execute, executeClaudeNonStream and ExecuteStream all assign the validated
original payload to the request and then translate both values. Since both
translations saw the same bytes, every Antigravity request paid for a second
full scan of the client payload. On a captured 24MB tool-history request that
second pass cost roughly 0.9s of CPU and 651MB of allocations.
Translate once when both inputs share a backing array and hand the caller an
independent duplicate, because later stages edit the working copy in place.
Payloads that genuinely differ still get two translations.
- Add `is-compat` support to OpenAI compatibility model config, capabilities, hashing, and example config.
- Propagate `IsCompat` through API-key model resolution and switch OpenAI-compat executor translation to compatibility-aware routing.
- Keep Claude assistant thinking content in compatibility mode while keeping default behavior unchanged when `is-compat` is disabled.
Closes: #4776
- Added `is-compat` model metadata plumbing from config through executor and helpers, including hash computation.
- Introduced a compatibility-aware translation path (`TranslateRequestWithAPIKeyModelCompatibility`) and wired it into Claude/Gemini/Codex/Interactions request flows.
- Updated Claude message sanitization/translation behavior to keep empty-thinking compatibility blocks (including signatures) when `is-compat` is enabled, while keeping default behavior unchanged.
- Updated Kimi and Gemini executors to use `TranslateRequestWithCodexMultiAgentV2` for improved multi-agent v2 optimization.
- Enhanced configuration and API server to support `CodexOptimizeMultiAgentV2`.
- Added codex multi-agent V2 optimizations in `config`, `executor`, and `watcher` modules.
