dsh-hashline-edittool: Hash Anchor Editing Tool for DeepSeek Harness

dsh-hashline-edittool is a plugin for DeepSeek Harness (DSH), designed to address the context waste and instruction failures associated with traditional line-number-based editing. It uses a content-hash-based anchor mechanism (dynamically Base62-encoded) that enables models to perform precise edits via anchors, avoiding redundant output of old code and providing atomic batch writes. The plugin supports Tree-sitter AST editing, LSP semantic information, and self-rendered UI, with content staleness detection and rollback. By replacing the original built-in tools with `read` and `edit` tools, it is easy to install and well suited to development scenarios involving complex, multi-step code editing.