dsh-game-hud: DSH Game Style Floating HUD Plugin

`dsh-game-hud` is a DeepSeek Harness plugin designed for the DSH web profile, aiming to display key states centrally via a game-style floating HUD to reduce the cost of switching between multiple pages for developers. Its core features include intuitively displaying account balance (default full bar ¥20, cached by the host for 30 seconds) and the remaining current session context using health and mana bars, respectively. It provides real-time monitoring of peak and valley pricing and switching countdowns (peak hours are 09:00–12:00 and 14:00–18:00; valley hours are half price). Red light alerts are triggered when the balance is below a threshold. Furthermore, it automatically triggers compression when the remaining context is below 5%; after two consecutive rounds, "start a new session with memory" can be selected to achieve seamless continuity by silently injecting a memory summary. This plugin supports via `dsh plugin`