Core Join/Leave buttons' enabled state is driven by the same broken join-status detection as #2748

Core Join/Leave buttons' enabled state is driven by the same broken join-status detection as #2748

Where: Same file as bug #2748 , SMBActiveDirectory.page.

The bug: the Join/Leave buttons' disabled state is computed as:

$adJoined = $var['joinStatus'] == "Joined";
...
<input type="submit" name="cmdJoinDomain" value="_(Join)_" <?=$adJoined ? "disabled" : "";?>>
<input type="submit" name="cmdLeaveDomain" value="_(Leave)_" <?=$adJoined ? "" : "disabled";?>>

Since $var['joinStatus'] is the same underlying detection that
inaccurately reports "Not joined" on boxes that are genuinely, actively
joined (the original motivating inaccuracy behind our own
net ads testjoin-based status check), $adJoined is effectively
always false in practice.

Impact, two distinct consequences:

• Join is always clickable, even on an already-joined box, inviting
  users to trigger an unnecessary rejoin (and, per bug #2748 , an
  unnecessary array stop) on a connection that was already fine.
• Leave is always disabled. There is no way to leave the domain
  through Unraid's stock UI at all, for as long as the underlying
  detection remains broken — not a cosmetic issue, a genuine missing
  capability.

How we found it: noted while reviewing the same file for bug #2748 ;
directly connects to the original status-display inaccuracy that
motivated this fork's own accurate join-status feature in the first
place.

Suggested fix: fix the underlying joinStatus detection (the same
fix needed for the display inaccuracy) — both consequences share one
root cause.

Our workaround: since our own plugin already computes an accurate
join status via net ads testjoin's exit code (not joinStatus's
apparent detection method, whatever that is), our own replacement UI
correctly enables/disables Join vs. Leave based on real state, for the
already-in-ads-mode case our replacement covers.

Start in SMBActiveDirectory.page and trace how joinStatus is detected, alongside the related fix described in bug #2748. Compare that state with the net ads testjoin exit code mentioned in the issue. Done means Join is disabled for an already-joined box, Leave is enabled there, and the inverse applies when it is not joined.