Caliper: Responsive UI Regression Tests

Cross-device responsive UI failures move buttons offscreen on rotation, lose controller focus, and still look fine on desktop. Caliper builds a repeatable suite from the profiles available in your Studio build: phone, tablet, desktop, and console cases in supported orientations. Each Play test captures PlayerGui geometry and checks pointer, keyboard, controller, and text input through a temporary Caliper fixture. Save a baseline. The next run reports geometry, visibility, focus, rule, and input changes, with old and current rectangles together. Its local receipt names each case, resolution, input result, baseline digest, failure, and delta. Bounded repairs open in a review sheet first. Caliper rejects stale targets, applies the reviewed set in one undo recording, and keeps a recovery record for restore or discard. Requires Studio Edit mode. Each case has a 20-second limit; capture stops at 5,000 GuiObjects. No HTTP, screenshots, multiplayer test, or gameplay-flow automation.