Fix: Pass $serverTimezone to shouldRunNow() in ServerCheckJob dispatch

Pass the server timezone parameter to shouldRunNow() call at line 127,
ensuring ServerCheckJob dispatch respects the server's local timezone
instead of falling back to the instance default.

This aligns the behavior with other scheduled tasks in the same method:
- ServerStorageCheckJob (line 137)
- ServerPatchCheckJob (line 144)
- Sentinel restart (line 152)

All scheduled tasks in processServerTasks() now consistently use the
server's configured timezone for cron evaluation.

Added unit test to verify timezone-aware cron schedule evaluation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Jobs/ServerManagerJob.php

@@ -124,7 +124,7 @@ class ServerManagerJob implements ShouldQueue
 
         if ($sentinelOutOfSync) {
             // Dispatch ServerCheckJob if Sentinel is out of sync
-            if ($this->shouldRunNow($this->checkFrequency)) {
+            if ($this->shouldRunNow($this->checkFrequency, $serverTimezone)) {
                 ServerCheckJob::dispatch($server);
             }
         }