fix(wsl): normalize Windows paths during update (#6086) (#6097)

When running under WSL, the update command could receive Windows-style
absolute paths (e.g., `C:\...`) and pass them to Linux processes
unchanged, which fails because WSL expects those paths in
`/mnt/<drive>/...` form.

This patch adds a tiny helper in the CLI (`cli/src/wsl_paths.rs`) that:
- Detects WSL (`WSL_DISTRO_NAME` or `"microsoft"` in `/proc/version`)  
- Converts `X:\...` → `/mnt/x/...`  

`run_update_action` now normalizes the package-manager command and
arguments under WSL before spawning.
Non-WSL platforms are unaffected.  

Includes small unit tests for the converter.  

**Fixes:** #6086, #6084

Co-authored-by: Eric Traut <etraut@openai.com>

codex-rs/cli/src/main.rs

@@ -26,8 +26,10 @@ use std::path::PathBuf;
 use supports_color::Stream;
 
 mod mcp_cmd;
+mod wsl_paths;
 
 use crate::mcp_cmd::McpCli;
+use crate::wsl_paths::normalize_for_wsl;
 use codex_core::config::Config;
 use codex_core::config::ConfigOverrides;
 use codex_core::features::is_known_feature_key;
@@ -270,7 +272,11 @@ fn run_update_action(action: UpdateAction) -> anyhow::Result<()> {
     let (cmd, args) = action.command_args();
     let cmd_str = action.command_str();
     println!("Updating Codex via `{cmd_str}`...");
-    let status = std::process::Command::new(cmd).args(args).status()?;
+    let command_path = normalize_for_wsl(cmd);
+    let normalized_args: Vec<String> = args.iter().map(normalize_for_wsl).collect();
+    let status = std::process::Command::new(&command_path)
+        .args(&normalized_args)
+        .status()?;
     if !status.success() {
         anyhow::bail!("`{cmd_str}` failed with status {status}");
     }