dsh-token-cost-meter: Display token usage and estimated costs in DSH sessions

`dsh-token-cost-meter` is a DSH plugin designed to display the cumulative Token consumption of the current session and the estimated cost in RMB based on DeepSeek's official pricing in real-time below the input box of the Web GUI. The plugin supports two modes: the installed version `dsh.bundle` and the dynamic `cordis_define`. Core functions include reading Token usage from the session projection (missed input, cache hit, and output), and dynamically fetching the DeepSeek official price page every 6 hours to automatically switch peak and valley prices based on Beijing Time. If the fetch fails, it falls back to a built-in snapshot and marks this on the interface. The cost calculation formula is: Missed Input Quantity × Missed Price + Cache Hit Quantity × Hit Price + Output Quantity × Output Price. Installation requires DSH WebGUI.