dsh-tool-squeeze: Evidence-Preserving Output Compression Plugin for DeepSeek Harness

`dsh-tool-squeeze` is an evidence-preserving compression plugin for DeepSeek Harness (DSH). It runs after tool execution and compresses outputs such as logs and JSON using local deterministic algorithms, prioritizing the retention of errors, warnings, and structured samples. The plugin does not rely on an LLM and retains original content via the Spill Store, ensuring that key root-cause information is not lost while reducing context tokens. It can be installed and configured through the plugin manager.