fix(computer): show ✓ check after a successful Test (not a stuck spinner)

When the user clicks Test, the button now transitions spinner → ✓ (green) on
success / ✗ (red) on failure (persisting until the next test or computer
change), instead of reverting to plain 'Test' text with no success indicator.

Also refresh the connection-status badge immediately after a test completes, so
a stale 'connecting' spinner caught by the 4s poll mid-test is cleared and the
badge reflects the real post-test state. Clear the test result when the selected
computer changes so a stale ✓ from alias A doesn't persist for alias B.

0 files changed, 0 insertions, 0 deletions