feat(jobs): improve scheduled tasks with retry logic and queue cleanup

- Add retry configuration to CoolifyTask (3 tries, 600s timeout)
- Add retry configuration to ScheduledTaskJob (3 tries, configurable timeout)
- Add retry configuration to DatabaseBackupJob (2 tries)
- Implement exponential backoff for all jobs (30s, 60s, 120s intervals)
- Add failed() handlers with comprehensive error logging to scheduled-errors channel
- Add execution tracking: started_at, retry_count, duration (decimal), error_details
- Add configurable timeout field to scheduled tasks (60-3600s, default 300s)
- Update UI to include timeout configuration in task creation/editing forms
- Increase ScheduledJobManager lock expiration from 60s to 90s for high-load environments
- Implement safe queue cleanup with restart vs runtime modes
  - Restart mode: aggressive cleanup (marks all processing jobs as failed)
  - Runtime mode: conservative cleanup (only marks jobs >12h as failed, skips deployments)
- Add cleanup:redis --restart flag for system startup
- Integrate cleanup into Dev.php init() for development environment
- Increase scheduled-errors log retention from 7 to 14 days
- Create comprehensive test suite (unit and feature tests)
- Add TESTING_GUIDE.md with manual testing instructions

Fixes issues with jobs failing after single attempt and "attempted too many times" errors

app/Models/ScheduledTask.php

@@ -12,6 +12,14 @@ class ScheduledTask extends BaseModel
 
     protected $guarded = [];
 
+    protected function casts(): array
+    {
+        return [
+            'enabled' => 'boolean',
+            'timeout' => 'integer',
+        ];
+    }
+
     public function service()
     {
         return $this->belongsTo(Service::class);