Move `load_workspace_dependencies` and the primary-runtime payload logic out
of `apps/desktop-host` into `@deepseek-ai/dsh-tool-workspace-dependencies`
so profiles other than Desktop can mount the same tool. Desktop keeps its
behavior through the package.
Two additions for carriers that are not Electron applications:
- `root` is optional: without it the payload is validated and used in place
(no copy under the Harness home), which suits read-only container layers.
- `runtime.json` accepts `linux`, and the `node` / `pnpm` components are
optional; the returned paths and the tool output omit what the payload
does not ship.
The `sdk` profile mounts the tool and `@deepseek-ai/dsh-skill-office` when
`DSH_PRIMARY_RUNTIME` names a payload directory (its sibling `office-skills/`
carries the skill resources); both rows stay disabled otherwise. Both
packages join the Python runtime closure.
fz