dsh-pi-compatible: Pi Tool Group Contract Replication Plugin

`dsh-pi-compatible` is a plugin for DeepSeek Harness (DSH), designed to replicate the tool interaction contract of Pi Agent while preserving DSH's underlying capabilities. It provides two presets: “Core” and “Plus.” “Core” replicates the seven core tools from Pi 0.84.2 (such as read, bash, edit, write, grep, find, and ls); “Plus” adds extended features such as WebFetch and WebSearch on top of that. Its underlying capabilities cover file systems, subprocesses, session management, and more. Installation must be performed via the Web profile, requires external tools such as Bash, fd, and rg, and requires `danger-full-acce`