@lhh666-6

DSH update checker for the DSH Desktop installer channel and GitHub source releases, with one-click download/update.

Paste/drop files into the DSH composer, save them under the current workspace, and insert relative paths.

Fix DSH Desktop copy buttons by bridging clipboard writes to the Electron main process.

Real-time DeepSeek token usage and cost meter for DSH: status-bar capsule plus detail panel, local-only persistence.