dsh-ssh-files-sidebar: Remote SSH Workspace and Deployment Agent for DeepSeek Harness

The DeepSeek Harness plugin `dsh-ssh-files-sidebar` is a Remote SSH Workspace that integrates file management, terminal operations, and a complete deployment lifecycle. It supports browsing, editing, and uploading remote files, as well as running terminal commands. The plugin includes a built-in Zero-to-One Bootstrap feature that analyzes local and remote environments to generate a deployment plan. Once confirmed by the user, the plan is persisted as `DEPLOYMENT.md`, enabling a shift from manual operations to automated release management. After installation, it allows developers to work locally while using Linked SSH to manage remote services and logs, and to leverage the Agent for autonomous deployment and rollback.