feat: add dedicated deploy logging to storage/logs/deploy.log

- Add 'deploy' channel in logging.php
- Instrument DeployTask with phpLog() for all state transitions
- Instrument DeploySiteAction with channel('deploy') for triggers, errors, clears
- Logs written to storage/logs/deploy.log (separate from laravel.log)

config/logging.php

@@ -118,6 +118,13 @@ return [
             'replace_placeholders' => true,
         ],
 
+        'deploy' => [
+            'driver' => 'single',
+            'path' => storage_path('logs/deploy.log'),
+            'level' => 'info',
+            'replace_placeholders' => true,
+        ],
+
         'null' => [
             'driver' => 'monolog',
             'handler' => NullHandler::class,