Propagate permission approval environment id (#25862)

## Stack

1. #25850 - Key request-permission grants by environment: stores and
applies sticky permission grants per environment id.
2. #25858 - Add `environmentId` to `request_permissions`: lets the model
target a selected environment and resolves relative permission paths
against it.
3. This PR (#25862) - Propagate permission approval environment id:
carries the selected environment id through approval events, app-server
requests, TUI prompts, and delegate forwarding.
4. #25867 - Add remote request permissions integration coverage:
verifies the selected remote environment across request, approval, grant
reuse, and exec.

This PR is stacked on #25858, and #25867 is stacked on this PR.

## Why

PR2 lets the model bind a `request_permissions` call to a selected
environment, but the approval event and client-facing request still
needed to carry that binding. For CCA, the user-facing prompt and
delegated approval path should know which environment the grant applies
to instead of relying on cwd alone.

## What Changed

- Added optional `environmentId` to `RequestPermissionsEvent`.
- Emit the selected environment id from core permission approval events.
- Preserve the environment id through delegate forwarding, including
cwd-based delegated requests.
- Added `environmentId` to app-server permission approval params,
generated schema/TypeScript artifacts, and README examples.
- Preserve and display the environment id in TUI permission approval
prompts.
- Updated focused core, app-server protocol, and TUI conversion
coverage.

## Testing

Not run locally per instruction. Performed read-only `git diff --check`.

codex-rs/tui/src/chatwidget/tests/approval_requests.rs

@@ -281,6 +281,7 @@ fn app_server_request_permissions_preserves_file_system_permissions() {
         thread_id: "thread-1".to_string(),
         turn_id: "turn-1".to_string(),
         item_id: "item-1".to_string(),
+        environment_id: Some("remote".to_string()),
         started_at_ms: 0,
         cwd: cwd.clone(),
         reason: Some("Select a workspace root".to_string()),
@@ -310,6 +311,7 @@ fn app_server_request_permissions_preserves_file_system_permissions() {
         }
     );
     assert_eq!(request.cwd, Some(cwd));
+    assert_eq!(request.environment_id.as_deref(), Some("remote"));
 }
 
 #[tokio::test]

codex-rs/tui/src/chatwidget/tool_requests.rs

@@ -441,6 +441,7 @@ impl ChatWidget {
             thread_id: self.thread_id.unwrap_or_default(),
             thread_label: None,
             call_id: ev.call_id,
+            environment_id: ev.environment_id,
             reason: ev.reason,
             permissions: ev.permissions,
         };