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/utils/path-uri/src/tests.rs

@@ -119,6 +119,11 @@ fn inferred_native_path_string_uses_the_inferred_convention() {
             expected,
             "rendering {uri}"
         );
+        assert_eq!(
+            LegacyAppPathString::from(path).as_str(),
+            expected,
+            "rendering typed API path {uri}"
+        );
     }
 }