feat: change default PR branch prefix to laravelplus-updater-

- Updated default pr_branch_prefix from 'upstream-sync-' to 'laravelplus-updater-'
- Updated both UpstreamPrCommand.php and upstream.php config
- PR branches now use format: laravelplus-updater-YYYY-MM-DD-HH-MM-SS
- Better branding and identification of LaravelPlus Updater PRs
- Maintains backward compatibility via UPSTREAM_PR_BRANCH_PREFIX env var

Example: laravelplus-updater-2025-10-13-09-17-27

Author: nejc

src/Config/upstream.php

@@ -89,7 +89,7 @@
     |
     */
     'create_pr' => env('UPSTREAM_CREATE_PR', false),
-    'pr_branch_prefix' => env('UPSTREAM_PR_BRANCH_PREFIX', 'upstream-sync-'),
+    'pr_branch_prefix' => env('UPSTREAM_PR_BRANCH_PREFIX', 'laravelplus-updater-'),
     'pr_title' => env('UPSTREAM_PR_TITLE', 'chore: sync from upstream'),
     'pr_body' => env('UPSTREAM_PR_BODY', 'Automated upstream sync from {upstream_url}'),
     'github_token' => env('GITHUB_TOKEN'),

src/Console/Commands/UpstreamPrCommand.php

@@ -232,7 +232,7 @@ private function generatePrBranchName(array $cfg): string
             return $customBranch;
         }
 
-        $prefix = $cfg['pr_branch_prefix'] ?? 'upstream-sync-';
+        $prefix = $cfg['pr_branch_prefix'] ?? 'laravelplus-updater-';
         $timestamp = now()->format('Y-m-d-H-i-s');
 
         return $prefix.$timestamp;