Issue 9: JMeter performance tests + JFR tracing

Description: Simulate realistic usage of Sztab via JMeter and analyze performance bottlenecks using Java Flight Recorder (JFR). This provides a baseline for tuning and future scalability work.

Tasks:

•  Design JMeter test plan:
  • Concurrent user logins
  • Create/update issues
  • List issues by project, status, assignee
•  Export .jmx JMeter test plan and check into repo (under performance/)
•  Run JMeter tests against local or dev Kubernetes deployment
•  Enable Java Flight Recorder (JFR) in the running container
•  Capture .jfr recording during test execution
•  Analyze performance with Java Mission Control (JMC):
  • GC activity
  • Lock contention
  • Thread pool utilization
  • Memory usage
•  Document results and bottlenecks (if any)
•  Optionally, integrate JMeter test execution into CI/CD for regression detection

Estimated Effort: 6–8 hours