dsh-pwsh-quoting-guard: Resolving PowerShell Command String Quote Escaping Issues

`dsh-pwsh-quoting-guard` is a plugin that solves the quoting and escaping challenges when DSH executes PowerShell commands on Windows. By using a structured data transfer mechanism, it moves the escaping burden from the model to the tool layer. Its core tools include `pwsh_script`, which passes scripts via `$DSH_ARGS`, and `run_argv`, which passes arguments directly, ensuring accurate execution of complex paths and special characters. The plugin supports UTF-8 encoding and requires restarting `dsh web` after installation to take effect.