jkt-check/dsh-secret-scrub: DeepSeek Harness Irreversible Ciphertext Scrubbing Plugin

`dsh-secret-scrub` is a sensitive data scrubbing plugin for DeepSeek Harness (DSH). It uses regex matching to replace sensitive data (e.g., API keys and tokens) with irreversible placeholders in the form `[REDACTED:<category>]` to prevent data leakage. The plugin offers three scrubbing levels—minimal, balanced (default), and aggressive—supports custom rules, and monitors user messages, tool results, and logs for interception. Although it can be used as a standalone plugin, users should be aware of its irreversibility and the limitations of regex matching (such as false positives and inability to detect unencoded keys), and should not rely on this plugin alone as the sole leakage-prevention measure.