Fix Gravity Split and Bond interaction regressions

[ganesh47]

Summary

• consume Bond Blast clap events even before completion so stale early claps cannot block the completion clap
• add locked Gravity Split auto-advance scheduling and real tilt-driven split adjustments
• prevent locked SplitView bucket taps from mutating the split

Validation

• xcodebuild test -project Mather.xcodeproj -scheme Mather -destination "id=44625752-9C3D-45D3-9CF6-816085B49EA2" CODE_SIGNING_ALLOWED=NO -only-testing:MatherTests -skip-testing:MatherTests/SumSprintEngineTests/timeoutMarksCardAsTimedOut on studio passed: 694 tests in 79 suites
• A prior full MatherTests run without the skip compiled and ran the new tests, but SumSprintEngineTests.timeoutMarksCardAsTimedOut failed once; rerunning with the same target showed that test passing, so I treated it as an existing timer flake and did not change Sum Sprint in this slice.

Refs #1117