dsh-entry-drawer: Toggle to collapse the sidebar entry list

As more global panel entries are added to the left sidebar of DSH, the session history gets pushed down. The `dsh-entry-drawer` does not add new features; it merely utilizes the `sidebar.panellist` slot to place a row of toggle switches at the very beginning of the entry list. Clicking them hides all other entries as a whole, moves the session history up, and restores the state when clicked again. The collapsed state is saved to cookies and localStorage, ensuring persistence across ports and restarts. The plugin has no build steps; its logic is concentrated in `client.js`: it registers a row with an order of -1000, intercepts clicks during the capture phase, dynamically writes a CSS rule based on `nav[aria-label]`, and includes a safety panel. Targeted for DSH 0.2.x, version 0.1.0 on npm, licensed under MIT, and supporting three installation methods: npm, GitHub, and local directory. The text also lists six known limitations: reliance on navigation accessibility names, interception occurring outside of React, hiding the entire group, ineffectiveness on narrow sidebars, fragile directory installation, and state storage per browser. Source code and the license should be reviewed before installation.