hellosz/dsh-pets: Codex Pets Style Plugin for DSH Web GUI

`hellosz/dsh-pets` is a DeepSeek Harness (DSH) Web GUI plugin licensed under the MIT License, designed to visually present agent task status through pet animations. The plugin introduces 10 built-in pets, using 9 state animations (such as thinking, waiting, reviewing, error, etc.) to replace traditional progress indicators, helping users quickly identify the current phase of an Agent during long tasks, approvals, or code reviews. Key features include: pets support drag-and-drop, click interaction, and one-click hiding; the settings page allows users to switch pets and adjust zoom ratios from 0.6x to 2.5x; it supports petdex-compatible custom pet package formats (8x9 spritesheet). The plugin only listens to DSH events without blocking the workflow, and provides status queries via a web interface.