dsh-tool-tariff: DSH Peak/Valley Time Period Query and Balance Reminder Plugin

# Preface If you want to schedule tasks to run during off-peak hours and finish before peak hours arrive, you need to be constantly aware of whether it is currently peak or off-peak and when the next switch will occur. Existing methods involve maintaining a schedule manually and cross-referencing it, which is cumbersome and prone to error; similarly, checking the remaining balance of the DeepSeek API requires interrupting your current work. `dsh-tool-tariff` is a DSH (DeepSeek Harness) plugin that integrates these functions into the session: the model can directly answer time-related queries, automatically reminds you before peak hours, and a real-time status badge remains in the top bar of the Web GUI. DSH's philosophy is "Everything is a plugin," making this capability suitable for mounting as a plugin. The following sections introduce the features, installation, configuration, usage, and precautions in that order. # What is this d