dsh-pdf: Reading PDF Text, Metadata, and Page Ranges Locally in DeepSeek Harness

`sunshine-lang/dsh-pdf` is a DeepSeek Harness (DSH) plugin licensed under MIT, designed to locally parse PDF files. It leverages PDF.js to extract text, metadata (such as title and total page count), and content from specified page ranges in an offline environment, without requiring an API key or network connection. Its core functionality includes the `pdf_read` tool, which supports text extraction page by page with page number annotations and allows flexible selection of page ranges via formats like `"1-3,5"` or `"all"`. To ensure security and efficiency, the plugin incorporates built-in limits for file byte size (default: 20 MiB), maximum pages per parse (default: 500 pages), and maximum characters per invocation (default: 12,000 characters), triggering an error when these limits are exceeded.