[Test] Add packager port setting status coverage

[ConnorQi01]

Summary

Add focused test coverage for the packager port setting-change behavior and the status bar pending-port indicator.

This issue is separate from the implementation issue so the test-only changes can be reviewed independently as a stacked PR.

Proposed Changes

• Cover configuration changes while packagers are stopped so the cached port is refreshed silently.
• Cover configuration changes while packagers are active so the running port is preserved and the status indicator marks the pending restart state.
• Cover unrelated configuration changes.
• Cover status bar warning text and tooltip when a pending packager port is present.
• Cover clearing the pending warning after the new port is applied.

Test Plan

• Run npm run build.
• Run npm test and confirm the new tests pass. Existing environment-dependent failures may remain unrelated.