dsh-evidence-gate: DeepSeek Harness Evidence Gate Plugin

`dsh-evidence-gate` is an audit plugin for DeepSeek Harness designed to enforce that agents reach conclusions through a structured evidence hierarchy and cross-checks, eliminating hallucinations based on unverified guesses. The plugin provides a three-layer evidence policy, a persistent session-level ledger, and a false-positive prevention ladder, with toggles available via command line and UI. After installation, it must be enabled in the configuration; it can generate detailed session reports and is suitable for scenarios that require high reliability and strict auditing.