RemSound latency lab - measuring depth-target convergence with the shipped playout code.
Raise under test: 30ms -> 330ms. Expected growth at full depth-bias: ~3ms/s.

--- T3 classic app path: WASAPI lane active, slider drives Mixed ---
  session route after arrival: WasapiLane  (slider writes to: Mixed)
  settled at slider 30ms: buffered=70ms
  t+10s buffered=  48ms
  t+20s buffered=  66ms
  t+30s buffered= 114ms
  t+40s buffered= 125ms
  t+50s buffered= 165ms
  t+60s buffered= 194ms
  RAISE via slider: 70ms -> 194ms in 60s = 2.07ms/s  GROWS (slider works)
  LOWER via slider: back to 30ms -> buffered=48ms after 3s


=== SUMMARY ===
  T3 classic app path: WASAPI lane active, slider drives Mixed: raise 2.07ms/s [GROWS (slider works)], lower -> 48ms