Review catch (Copilot, PR #2039): folding the rejected disconnect into
`connectError` meant nobody ever saw it. InfoTab renders that value only
when `serverState.status === "error"`, and a failed disconnect leaves the
status "connected" — so the message existed in state and never on screen.
Worse, it fed `connectError ?? inspectorLastError`, where a stale value
would go on masking a later, real connection error.
Give it its own `disconnectError` state and a header banner that renders
regardless of status, cleared on the next connect or disconnect attempt
and on a server switch, so it can neither linger nor be attributed to
the wrong server. The tests now assert the rendered banner rather than
noting that nothing is visible.
Signed-off-by: cliffhall <cliff@futurescale.com>
5d8094357d