feat: Implement cron job queue system based on database

- Added PHP support to project configuration.
- Updated FTP configuration to exclude additional directories.
- Changed remote database host in config.php and enabled debug mode.
- Removed outdated TODO from documentation and created a new CRON_QUEUE_PLAN.md.
- Introduced a new cron job queue system using database tables pp_cron_jobs and pp_cron_schedules.
- Refactored cron job orchestration to improve management and reliability.
- Updated OrderAdminService to use the new queue system and removed old file-based logic.
- Added migration scripts for new database structure.

.vscode/ftp-kr.json

@@ -14,6 +14,10 @@
     ".git",
     ".svn",
     "/.vscode",
-    "/temp/*"
+    "/temp",
+    "/.serena",
+    "/.claude",
+    "/docs",
+    "/tests"
   ]
 }