dsh-sandbox-allowlist: Add configurable authorized directories for the DSH default sandbox

dsh-sandbox-allowlist is an extension plugin for DSH, designed to maintain default sandbox security boundaries while solving the issue where CLI commands and write/edit tools within the sandbox struggle to write to trusted directories outside the workspace. This plugin allows secure writes to specified directories without requiring the sandbox to be shut down or step-by-step approval. Its core features include support for wildcard configuration of multiple authorized directories, coverage of both Windows ACL and Linux bwrap platforms, and real-time configuration editing. The plugin adopts a pure plugin mechanism that does not modify official code and provides scripts for automatic authorization revocation and emergency cleanup on Windows. Users need to install the plugin via the dsh command line and configure authorizations in settings.yaml.