fix(workers): drop $redis property overrides that break PHP 8.2+ covariance

Regression hotfix for #1022. Commit bc4875c introduced
`protected mixed $redis = null;` on WorkerBase as part of the Redis
connection hardening work (code review HIGH #2: Injectable::__get can
resurrect a socket inside destructors unless the property is declared).
That was correct in isolation, but three child classes already had
their own legacy `protected $redis;` declaration without a type, and
PHP 8.2+ property-type covariance requires the type to match exactly
through the whole inheritance chain. Starting from the next cron tick
after bc4875c hit a PHP 8.2+ server, loading any of the following
classes produced a fatal:

  Type of MikoPBX\Core\Workers\Cron\WorkerSafeScriptsCore::$redis
  must be mixed (as in class MikoPBX\Core\Workers\WorkerBase)
  in /offload/rootfs/usr/www/src/Core/Workers/Cron/WorkerSafeScriptsCore.php:68

Same fatal on WorkerExtensionStatusMonitor and WorkerProviderStatusMonitor.

Concrete impact observed on serber@boffart.miko.ru:

- WorkerSafeScriptsCore is the watchdog that cron fires every minute.
  Every cron tick produced four stacked Whoops fatals (one per parallel
  instance) in /storage/usbdisk1/mikopbx/log/system/messages and exited
  before doing any work. New watchdog instances could not start.
- The existing pre-regression watchdog process (the one that had been
  loaded into memory BEFORE bc4875c was deployed) kept running on
  stale bytecode, so supervision continued to "work" until it would
  eventually die — at which point the whole worker pool would lose its
  babysitter silently.
- WorkerExtensionStatusMonitor and WorkerProviderStatusMonitor hit the
  same fatal on every status check; they are used for page-activity
  tracking in the admin cabinet.
- Module safe.php cron jobs that share the core worker bootstrap were
  affected by the same covariance check on every minute tick.

Fix is the minimal diff: delete the untyped `protected $redis;`
override in the three child classes. They now inherit the typed
`protected mixed $redis = null;` from WorkerBase, which is
semantically identical to their old behaviour (mixed accepts anything
including \Redis and Phalcon cache wrappers) and satisfies the PHP 8.2+
covariance rule. A short comment is left at each site so nobody
reintroduces the override by accident.

Verified on serber@boffart.miko.ru (MikoPBX 2026.1.233-dev, PHP 8.4.16):

1. Before: `class_exists('MikoPBX\Core\Workers\Cron\WorkerSafeScriptsCore')`
   throws `Whoops\Exception\ErrorException: ... must be mixed`.
2. After deploy: the same class_exists returns true, the direct
   `new WorkerSafeScriptsCore()` in a dry-run script constructs and
   clean-exits in 10 ms.
3. Pre-regression watchdog PID (30556) killed explicitly; cron respawned
   a fresh PID 5211 which picked up the hotfixed bytecode and is
   actively running the supervision loop (confirmed through
   `Checking worker pool: WorkerApiCommands - 3/3 instances running`
   and successful restarts of stale workers including
   WorkerRemoveOldRecords / WorkerS3CacheCleaner /
   WorkerNotifyAdministrator / ModuleCTIClient\WorkerSafeScript).
4. Zero new `must be mixed` fatals in syslog for the full observation
   window after the kill+respawn.

Swept the rest of src/Core/Workers for any other untyped `$redis`
overrides — none remain. `WorkerPoolManager::$redis` is declared
`private Redis $redis` and does not extend WorkerBase, so it is
unaffected.

Author: Alexey Portnov

src/Core/Workers/Cron/WorkerSafeScriptsCore.php

@@ -111,11 +111,9 @@ class WorkerSafeScriptsCore extends WorkerBase
      */
     private array $pingFailureCounts = [];
 
-    /**
-     * Redis connection instance
-     * @var \Redis
-     */
-    protected $redis;
+    // Redis handle inherited from WorkerBase::$redis (protected mixed, default null).
+    // A local override here would break PHP 8.2+ property type covariance —
+    // see hotfix for issue #1022 WorkerSafeScriptsCore::$redis regression.
 
     /**
      * Dedicated AMI connection for worker ping/pong checks.

src/Core/Workers/WorkerExtensionStatusMonitor.php

@@ -61,7 +61,8 @@ class WorkerExtensionStatusMonitor extends WorkerRedisBase
     ];
 
     private ?UserPageTrackerLib $pageTracker = null;
-    protected $redis;
+    // $redis inherited from WorkerBase (protected mixed $redis = null);
+    // a local untyped override would break PHP 8.2+ property-type covariance.
     private int $lastCheckTime = 0;
 
     /**

src/Core/Workers/WorkerProviderStatusMonitor.php

@@ -60,7 +60,8 @@ class WorkerProviderStatusMonitor extends WorkerRedisBase
     ];
 
     private ?UserPageTrackerLib $pageTracker = null;
-    protected $redis;
+    // $redis inherited from WorkerBase (protected mixed $redis = null);
+    // a local untyped override would break PHP 8.2+ property-type covariance.
     private int $lastCheckTime = 0;
 
     /**