Test code out of sync: looks for 'terminal-stub', which doesn't exist in the UI

[cat-hoang]

Problem
Frontend unit tests for shell toggle (ContainerRow.test.ts) expect a .terminal-stub class in the rendered DOM, but the component has since been reworked to use <ContainerTerminal> and .terminal-panel instead. Tests do not accurately verify Shell functionality.

Impact

• Test suite may give false sense of security or coverage for terminal features.

Recommendation

• Update the test suite to match real DOM structure and classnames rendered by ContainerTerminal.vue.
• Confirm the test actually verifies user flow (open/close Shell, typing, focus).