docs: sync OpenAPI reference from staging

[hanakannzashi]

Summary

• Sync the generated OpenAPI reference from staging while keeping the public server URL set to NEAR AI Cloud.
• Add API Reference navigation entries for the endpoints added by the schema.
• Exclude retiring Conversations, Files, and stateful Responses operations from both the published OpenAPI file and generated navigation.

Validation

• python3 -m py_compile scripts/sync-openapi.py
• git diff --check origin/main...HEAD
• jq empty api-reference/openapi.json
• jq empty docs.json
• Confirmed the generated sidebar has 118 operations and retains only POST /v1/responses from the Responses operations scheduled for removal.

[PierreLeGuen]

Thanks @hanakannzashi. The sync itself looks right: no operation was removed, and every operation in the spec is in the navigation (135).

One thing to change before merging: this publishes 20 operations we're about to retire. That's Conversations (11), Files (5), and the stateful Responses operations: GET and DELETE /v1/responses/{response_id}, /cancel, and /input_items.

Private Chat goes read-only on Sep 28, and your stateful-Responses removal (cloud-api#942, #943, #944) is planned for the Oct 1 release. Documenting them now points integrators at APIs we're removing. They're in the live spec, so the sync script picks them up. Suggest excluding the Conversations and Files tags and those four Responses operations in scripts/sync-openapi.py, then re-running the sync so the next one doesn't bring them back.

A question, not blocking: the new AML allowlist and report operations, and the org fallback ones, land in the public Admin group. They're admin-only, but do we want AML endpoints in the public reference? If not, the same exclusion list covers them.

[hanakannzashi]

Addressed the blocking request in c690296. The sync now filters Conversations, Files, and the four retiring stateful Responses operations before writing the OpenAPI file, so they stay out of both the published spec and sidebar on future syncs. I left AML and other Admin operations unchanged because that was raised as a non-blocking product-scope question.