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/tests/status_and_layout.rs

@@ -3573,7 +3573,7 @@ fn goal_status_indicator_line_formats_goal_text() {
             "Goal unmet (4K / 5K tokens)",
         ),
         (GoalStatusIndicator::Paused, "Goal paused (/goal resume)"),
-        (GoalStatusIndicator::Blocked, "Goal blocked (/goal resume)"),
+        (GoalStatusIndicator::Blocked, "Goal stalled (/goal resume)"),
         (
             GoalStatusIndicator::UsageLimited,
             "Goal hit usage limits (/goal resume)",