Show blocked goals as stalled in the TUI (#35886)

## What changed

- Display `Blocked` goal statuses as “stalled” in the goal menu and goal status footer.
- Update the goal menu snapshot and footer formatting test expectations.

GitOrigin-RevId: f3d8212d939f0d76354048231346328972226274

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

@@ -123,7 +123,7 @@ fn goal_status_label(status: AppThreadGoalStatus) -> &'static str {
     match status {
         AppThreadGoalStatus::Active => "active",
         AppThreadGoalStatus::Paused => "paused",
-        AppThreadGoalStatus::Blocked => "blocked",
+        AppThreadGoalStatus::Blocked => "stalled",
         AppThreadGoalStatus::UsageLimited => "usage limited",
         AppThreadGoalStatus::BudgetLimited => "limited by budget",
         AppThreadGoalStatus::Complete => "complete",