dsh-capability-index: Plugin library pre-check for DSH task-oriented requests

dsh-capability-index is a meta-plugin for DeepSeek Harness (dSH), designed to address the unpredictable tool utilization issue in multi-plugin scenarios. It employs a three-level consensus mechanism (semantic vector retrieval, rule vocabulary filtering, conflict prompting) to automatically inject Top-K plugin prompt blocks into the main session when task-oriented requests are triggered, while carrying `use_when`/`not_for` capability descriptions. The plugin adopts a read-only suggestion mode, does not force tool calls or rewrite definitions, and retains the final decision-making power on the model side. Its core functions include efficiently injecting prompts via the `runtime-context` channel, utilizing a local lightweight model (bge-small-zh-v1.5) for asynchronous semantic matching, and setting a `not_for` gate to filter conflicting candidates. The current version is v0.2, adopting...