dsh-compaction-pro: DeepSeek Harness High-Fidelity Context Compression Backend

The default compaction mechanism in DeepSeek Harness (DSH), `dsh-compaction-basic`, suffers from issues such as losing exact values and forcing English output. `dsh-compaction-pro` is an upgraded plugin that rewrites the summarization hook to achieve high-fidelity, bilingual, and recursive compaction. It enforces the preservation of numeric values, paths, and commands, supports Chinese summaries, and requires no changes to the original policy. Installation requires disabling the built-in backend and registering the plugin in the configuration file. This plugin is suitable for long sessions and can effectively address information loss and language fragmentation issues.