dsh-workspace-tree-status: Aggregated session status point of workspace tree directory rows

Although the DSH Web sidebar session rows feature status indicators, collapsing a folder hides the status of sub-sessions. The `dsh-workspace-tree-status` client plugin, maintained by ramwin, displays an aggregated status indicator to the left of each directory name in the workspace tree: yellow for pending interaction, green for unread completion, and a spinning gray circle for running. It illuminates only one indicator based on the priority order of pendingInteraction, completionUnread, and running. Nested workspaces aggregate status upward to parent directories based on path prefixes. Install via `dsh plugin --profile web add`; it requires no configuration. It merely decorates the DOM without writing to session data.