lwklbb/dsh-worktrees: Integrate Git worktree management into the DSH settings panel

# Introduction When developing with DSH, you often need to handle multiple branches of the same project simultaneously: keeping the main line on `main`, opening a branch for features, and another for fixing production issues. While Git worktrees solve this pain point by checking out multiple branches of the same repository into different directories, using the command line requires remembering paths and arguments, and managing scattered paths across the disk can be cumbersome. The `dsh-worktrees` introduced below brings this functionality into DSH's settings panel. # What is this? `dsh-worktrees` is a DSH plugin maintained by lwklbb, released under the MIT license, with the current version being 0.1.0. Its positioning can be summarized in one sentence: centralized management of Git worktrees in the DSH settings panel.