Preserve image detail in app-server inputs (#20693)

## Summary

- Add optional image detail to user image inputs across core, app-server
v2, thread history/event mapping, and the generated app-server
schemas/types.
- Preserve requested detail when serializing Responses image inputs:
omitted detail stays on the existing `high` default, while explicit
`original` keeps local images on the original-resolution path.
- Support `high`/`original` consistently for tool image outputs,
including MCP `codex/imageDetail`, code-mode image helpers, and
`view_image`.

codex-rs/cli/src/main.rs

@@ -1646,7 +1646,7 @@ async fn run_debug_prompt_input_command(
         .images
         .into_iter()
         .chain(cmd.images)
-        .map(|path| UserInput::LocalImage { path })
+        .map(|path| UserInput::LocalImage { path, detail: None })
         .collect::<Vec<_>>();
     if let Some(prompt) = cmd.prompt.or(interactive.prompt) {
         input.push(UserInput::Text {