dsh-native-playbook: Start with DeepSeek Harness's Built-in Tools Before Considering Plugins

dsh-native-playbook is a community plugin for DeepSeek Harness, designed to address the challenge of determining whether a capability is available during automation. It provides the `native_capability` tool to route tasks to official DSH tools and check whether the capability is in an `operational` state. By distinguishing five lifecycle facts—`shipped`, `mounted`, `visible`, `providerReady`, and `operational`—the plugin enables users to precisely determine whether the current environment meets the required conditions. Core features include routing common tasks such as background commands and session searches to native paths, and safely activating reviewed native paths, strictly limited to DSH 0.