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/src/transport_tests.rs

@@ -254,7 +254,7 @@ async fn command_execution_request_approval_strips_additional_permissions_withou
                     reason: Some("Need extra read access".to_string()),
                     network_approval_context: None,
                     command: Some("cat file".to_string()),
-                    cwd: Some(absolute_path("/tmp")),
+                    cwd: Some(absolute_path("/tmp").into()),
                     command_actions: None,
                     additional_permissions: Some(
                         codex_app_server_protocol::AdditionalPermissionProfile {
@@ -320,7 +320,7 @@ async fn command_execution_request_approval_keeps_additional_permissions_with_ca
                     reason: Some("Need extra read access".to_string()),
                     network_approval_context: None,
                     command: Some("cat file".to_string()),
-                    cwd: Some(absolute_path("/tmp")),
+                    cwd: Some(absolute_path("/tmp").into()),
                     command_actions: None,
                     additional_permissions: Some(
                         codex_app_server_protocol::AdditionalPermissionProfile {