Add 6 tests for instance descriptor generation: - No clients returns nil - PVE only with sorted order - PBS only - PMG only - All types combined - Nil scheduler/stalenessTracker safety Coverage: 60.7% → 62.5%
Add 6 tests for polling task result recording: - Nil monitor safety check - Success case resets counters - Failure case increments counters - Consecutive failures tracking - Success resets failure state - Nil internal maps don't panic Coverage: 53.7% → 97.6%