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/bottom_pane/footer.rs

@@ -540,7 +540,7 @@ pub(crate) fn goal_status_indicator_line(
             }
         }
         GoalStatusIndicator::Paused => "Goal paused (/goal resume)".to_string(),
-        GoalStatusIndicator::Blocked => "Goal blocked (/goal resume)".to_string(),
+        GoalStatusIndicator::Blocked => "Goal stalled (/goal resume)".to_string(),
         GoalStatusIndicator::UsageLimited => "Goal hit usage limits (/goal resume)".to_string(),
         GoalStatusIndicator::BudgetLimited { usage } => {
             if let Some(usage) = usage {