[Test] Add packager port setting status coverage

[ConnorQi01]

Summary

Add focused tests for the packager port setting change behavior introduced in #2629.

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 the status bar warning tooltip and clearing behavior after the new port is applied.

Test Plan

• npm run build
• npm test

Note: This PR is stacked on #2629 and should be reviewed after the feature PR.

Closes #2628