dsh-task-estimator: Session Title Bar Task Estimation Window

`dsh-task-estimator` is a DSH plugin for the DeepSeek Harness web GUI, designed to centrally display estimated task remaining time, token usage, and model-based costs (approx. CNY) via the session title bar. Its core features include heuristic estimation based on extrapolation of recent 5 rounds, model cost breakdowns supporting peak and off-peak pricing, AI smart estimation utilizing lightweight completion on the current model (including PERT three-point estimation and complexity tiering), and single-turn latency estimation displayed during Agent thinking. The plugin provides interaction methods such as hover display, click-to-pin, and keyboard shortcut toggling, and allows users to customize price tables, refresh intervals, and restore default settings. Note version differences during installation (e.g., v1.1.0 vs 1.1.1), and the plugin can be added via the command line.