Improve API reliability under low-traffic load

Intermittent 60-second delays could affect API requests and station status checks during low-traffic periods, caused by background processing competing with database connections as infrastructure scaled down between requests.

• Fixed background processing after run creation so it completes reliably without delaying or blocking subsequent requests
• Improved database connection handling for internal job processing, eliminating connection errors during idle-to-active transitions
• Added a 20-second limit on background database operations so a slow query can no longer stall a request slot