Preserve target-native cwd in permission approval requests (#42314)

## Why

Permission requests can originate in an environment whose path convention differs from the Codex host. Requiring the request working directory to be host-native prevents those requests from reaching interactive approval.

## What changed

- Carry the request `cwd` as a `LegacyAppPathString` through core events and the app-server protocol so the target environment's native representation is preserved.
- Convert the preserved value back to a `PathUri` when materializing permission grants.
- Regenerate the JSON and TypeScript protocol schemas for the updated `cwd` type.

## Testing

- Exercise the app-server permission request round trip with a target-native working directory across host path conventions.
- Verify remote permission requests retain their environment working directory and granted access still unblocks later execution.

GitOrigin-RevId: 97dc9707d9048883d20bab1b69c93871039f3188

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -4272,7 +4272,7 @@
       "$schema": "http://json-schema.org/draft-07/schema#",
       "properties": {
         "cwd": {
-          "$ref": "#/definitions/v2/AbsolutePathBuf"
+          "$ref": "#/definitions/v2/LegacyAppPathString"
         },
         "environmentId": {
           "default": null,