This patch adds the ability to snap to the frame range bounds in the VSE timeline, on by default. End frame snap location is offset by 1 to ensure the snap point aligns with the visible end frame boundary (otherwise e.g. right handle of strip would be one frame short). Timeline and preview snapping is also turned on by default using the same versioning block. Pull Request: https://projects.blender.org/blender/blender/pulls/135753