[codex] Assign response item IDs when recording history

[pakrym-oai]

Why

Client-created response items enter history without IDs, so their identity is lost across rollout persistence and resume. IDs should be assigned once at the history-recording boundary, while IDs returned by the server must remain unchanged.

The Responses API validates item IDs using type-specific prefixes. Locally generated IDs therefore use the matching prefix plus a hyphenated UUIDv7, keeping them valid while distinguishable from server-generated IDs. Because this changes persisted history and provider request shapes, the behavior is opt-in behind the under-development item_ids feature. Compaction triggers remain request controls whose API shape does not accept an ID.

What changed

• Register the disabled-by-default item_ids feature and expose it in config.schema.json.
• Make supported optional ResponseItem IDs serializable and expose them in the generated app-server schemas.
• When item_ids is enabled, assign an ID during conversation-history preparation if an item has no ID.
• Generate type-prefixed, hyphenated UUIDv7 IDs using the Responses API item conventions.
• Preserve existing server IDs without rewriting them.
• Persist assigned IDs in rollouts and include them in subsequent Responses requests.
• Remove the unsupported ID field from CompactionTrigger and document why it has no ID.
• Add integration coverage for enabled ID persistence, preservation of server IDs, and omission of generated IDs while the feature is disabled.

prepare_conversation_items_for_history is the single response-item ID allocation boundary.

Test plan

• just test -p codex-features
• just test -p codex-core response_item_ids_persist_across_resume_and_preserve_server_ids
• just test -p codex-core non_openai_responses_requests_omit_item_turn_metadata
• just test -p codex-core resize_all_images_prepares_failures_before_history_insertion
• just test -p codex-protocol
• just test -p codex-app-server-protocol
• just test -p codex-api azure_default_store_attaches_ids_and_headers

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Strip generated IDs for non-OpenAI providers

For configured Responses-compatible providers where provider.info().is_openai() is false, build_responses_request still only clears metadata, so these newly serializable IDs are sent on every recorded user/context/tool-output item. That changes the request shape for custom/non-OpenAI endpoints that previously received schema-only items and may reject arbitrary id fields; keep the locally generated IDs out of non-OpenAI provider requests just like the Codex metadata is stripped.

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