Swap "Start story from here" with "Test from here" in passage bar

Swap "Start story from here" with "Test from here" in passage bar: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). When working on a project, testing from a specific passage is an extremely common action (for example in order to confirm how new changes look)…