unified-exec: retain PathUri in command events (#28780)

## Why

App-server must report command events containing foreign-platform paths
without changing existing client or rollout path-string formats.

## What changed

- retain `PathUri` through exec command begin/end events
- convert cwd values to `LegacyAppPathString` at the app-server
compatibility boundary
- drop command actions with foreign paths and log them
- serialize rollout-trace cwd values using their inferred native path
representation
- restore Wine coverage for retained Windows cwd values and successful
completion

codex-rs/app-server-test-client/src/lib.rs

@@ -2092,7 +2092,7 @@ impl CodexClient {
             println!("< command: {command}");
         }
         if let Some(cwd) = cwd.as_ref() {
-            println!("< cwd: {}", cwd.display());
+            println!("< cwd: {cwd}");
         }
         if let Some(command_actions) = command_actions.as_ref()
             && !command_actions.is_empty()