gaor0605-kq/dsh-workspace-explorer

Adds a Chats/Files switch to the left-sidebar Workspace header that swaps the session list for a lazily loaded tree of the current session's workspace. Files and folders can be dragged into the composer as @path references; clicking a file opens the built-in preview; the right-click menu reveals a file in the system file manager or copies its path; entries carry VS Code-style Git status (modified, untracked, added, deleted, conflict, ignored) relative to the last commit.