Task: 3. Create layersurface_update_scale(LayerSurface *l) function
Date: 2026-07-06
Status: COMPLETED

Changes:
- src/peachwm.c:912-941 — static function with current_outputs max scale iteration
  - Guards, current_outputs iteration, fallback, safety guard, fabsf check
  - Marked __attribute__((unused)) until wired in later task
- src/peachwm.c:952 — l->current_scale initialized after client_set_scale() in commitlayersurfacenotify() initial-commit path

Verification: make debug — compiles cleanly, zero warnings