This makes it appopriate to use the OsSysCalls abstraction
in other areas of the code-base, such as hot-restart.

Signed-off-by: Greg Greenway <ggreenway@apple.com>

**Description**
This PR is a follow up of initial support for OpenAI's Responses API PR
and implements the following pending work.

- [x] Replace OpenAI SDK Union types with our own
- [x] Improve and add more openinference traces req/res atrributes and
configuration.

**Related PRs**
Related PR: #1649

---------

Signed-off-by: Sivanantham Chinnaiyan <sivanantham.chinnaiyan@ideas2it.com>

…sing (#1879)

**Description**

The `ResponseInputItemUnionParam.UnmarshalJSON` discriminator for `type:
"message"` only checked for an `"id"` field to identify output messages.
Assistant messages sent back in multi-turn conversation history (e.g.,
from Codex CLI) carry `output_text` content but no `"id"`. Without the
`"id"`, parsing fell through to input message types that don't support
output_text, causing `"failed to parse JSON for /v1/responses"`.

The fix adds a secondary check: if `role` is `"assistant"`, try parsing
as `ResponseOutputMessage` before falling through to input message
types.

Specific request payload block cause the issue:

```
{
      "type": "message",
      "role": "assistant",
      "content": [
        {
          "type": "output_text",
          "text": "Hi! I’m here and working. How can I help you with the codex repo or anything else?"
        }
      ]
    },
```

**Related Issues/PRs (if applicable)**
Related PR: #1791

---------

Signed-off-by: Xiaolin Lin <xlin158@bloomberg.net>
Co-authored-by: Dan Sun <dsun20@bloomberg.net>

**Description**
This commit adds a new field `context_management` introduced in the new
OpenAI's Responses API ref docs[^1] to the request schema.

[^1]:
https://developers.openai.com/api/reference/resources/responses/methods/create

**Related PRs**
- #1791

Signed-off-by: Sivanantham Chinnaiyan <sivanantham.chinnaiyan@ideas2it.com>
Co-authored-by: Ignasi Barrera <ignasi@tetrate.io>