core: strip image detail from Responses Lite requests (#27246)

## Summary

- Strip image `detail` fields from every Responses Lite request.
- Apply stripping to message images and function/custom tool-output
images.
- Transform only the formatted request copy without mutating stored
history.
- Preserve image URLs byte-for-byte, including HTTP(S) URLs, without
downloading, validating, or resizing them.
- Preserve all image `detail` fields for non-Responses-Lite models.

## Motivation

Responses Lite does not support image `detail` tags, so Codex must omit
them whenever `model_info.use_responses_lite` is enabled. This transport
requirement is independent of the `resize_all_images` feature.

Stored history retains the original detail values. This keeps
request-specific formatting isolated from conversation state and
preserves the information for local image preparation and
non-Responses-Lite requests.


#### [git stack](https://github.com/magus/git-stack-cli)
- ✅ `1` https://github.com/openai/codex/pull/27245
- ✅ `2` https://github.com/openai/codex/pull/27247
- 👉 `3` https://github.com/openai/codex/pull/27246
- ⏳ `4` https://github.com/openai/codex/pull/27266

codex-rs/core/src/client.rs

@@ -746,7 +746,7 @@ impl ModelClient {
         window_id: &str,
     ) -> Result<ResponsesApiRequest> {
         let instructions = &prompt.base_instructions.text;
-        let input = prompt.get_formatted_input();
+        let input = prompt.get_formatted_input_for_request(model_info.use_responses_lite);
         let tools = create_tools_json_for_responses_api(&prompt.tools)?;
         let reasoning = Self::build_reasoning(model_info, effort, summary);
         let include = if reasoning.is_some() {