dsh-task-notice: Agent Task Notification and Usage Statistics Plugin

The DeepSeek Harness (DSH) plugin `dsh-task-notice` is designed to address the pain points of delayed task feedback and fragmented cost control during agent execution. It provides webhook notifications, system banner prompts, and multi-dimensional Token consumption statistics and analysis by provider. Features include task completion and permission reminders, window switching suggestions, detailed usage analysis (such as break-even tracking and cost-effectiveness calculation), and flexible pricing management (supporting peak/off-peak pricing and custom multipliers). The plugin uses a draft-saving mechanism and takes effect after installation and restart.