HF RL Explorer

Add a dark-mode theme store to the frontend

Add a dark-mode theme store to the frontend: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). The web app is built with Tailwind configured for class-based dark mode (the dark variant activates when an ancestor element carries the dark CSS class). We want a small…

The task

The web app is built with Tailwind configured for class-based dark mode (the `dark` variant activates when an ancestor element carries the `dark` CSS class). We want a small, reusable piece of state that the UI can use to drive a light/dark theme toggle.

Part of FineEnvs/MiMo-V2.6-RL-harbor-code.