dsh-session-search-pro: DSH cross-session search plugin based on sessionQuery

# Introduction As you work with DSH for a long time, your session logs pile up. Questions like "How was that error resolved last time?" or "Where was that previous configuration written?" often have answers buried in the historical chat logs, but the agent itself cannot see them. Manually browsing session files requires dealing with complex formats and compression details, while writing your own scripts to scan files means you can't access the currently active session. `dsh-session-search-pro` takes a different approach: instead of reading session files directly, it utilizes the harness's built-in `sessionQuery` service to encapsulate "searching, listing, and reading sessions" into three agent tools. Below, I will introduce its capabilities, installation method, and actual performance under the default (stock) configuration. # What is dsh-session-