dsh-ui-workspace: Composable workspace primitives for DeepSeek Harness browser extension

`@ch4acko3/dsh-ui-workspace` is a workspace UI library designed specifically for the DeepSeek Harness UI browser plugin. Built on top of `dsh-ui-container`, it decomposes common complex interactions into composable UI primitives, including draggable panel stacks, recursive tree views, tabbed document editors, document renderers, and action entry points, while supporting VS Code-style resource manager behavior. This library focuses on resolving interface skeleton scaffolding issues, leaving product-specific navigation logic, data providers, commands, and style implementations to the user. When installing, `dsh-ui-container` must be installed first in the same DSH profile, followed by `dsh-ui-workspace`. Environment requirements: N...