Make user input blocking behavior explicit (#36410)

## Why

Clients need to know whether a `request_user_input` request must wait for an
explicit response or may auto-resolve. Using `autoResolutionMs` as that signal
conflated the blocking decision with timeout policy.

## What changed

- Add required `isBlocking` fields to user input protocol and app-server
  request payloads. Plan-mode requests are blocking, while requests from other
  enabled modes are non-blocking.
- Drive the TUI's auto-resolution behavior from `isBlocking` and remove
  `autoResolutionMs` from the model-facing tool schema.
- Deprecate `autoResolutionMs` while retaining it for compatibility, and treat
  legacy payloads without `isBlocking` as blocking.

## Testing

- Cover mode-derived blocking behavior, legacy deserialization, app-server
  forwarding, delegated requests, and TUI auto-resolution.

GitOrigin-RevId: 29aade657ef743065ec264376ba567a9b353d7d7

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

@@ -152,6 +152,7 @@ mod tests {
             item_id: call_id.to_string(),
             turn_id: turn_id.to_string(),
             questions: Vec::new(),
+            is_blocking: true,
             auto_resolution_ms: None,
         }
     }

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

@@ -649,6 +649,7 @@ async fn request_user_input_notification_overrides_pending_agent_turn_complete_n
                 description: "Update only Plan mode.".to_string(),
             }]),
         }],
+        is_blocking: true,
         auto_resolution_ms: None,
     });
 
@@ -679,6 +680,7 @@ async fn handle_request_user_input_sets_pending_notification() {
                 description: "Update only Plan mode.".to_string(),
             }]),
         }],
+        is_blocking: true,
         auto_resolution_ms: None,
     });
 

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

@@ -2051,6 +2051,7 @@ async fn request_user_input_interrupt_pauses_active_goal_turn() {
             item_id: "call-1".to_string(),
             turn_id: "turn-1".to_string(),
             questions: Vec::new(),
+            is_blocking: true,
             auto_resolution_ms: None,
         });