docs(readme): add hash-anchored Edit Tool to feature lists

README.md

@@ -167,6 +167,7 @@ Meet our main agent: Sisyphus (Opus 4.6). Below are the tools Sisyphus uses to k
   - Librarian: Official docs, open source implementations, codebase exploration (GLM-4.7)
   - Explore: Blazing fast codebase exploration (Contextual Grep) (Grok Code Fast 1)
 - Full LSP / AstGrep Support: Refactor decisively.
+- Hash-anchored Edit Tool: `LINE#ID` format validates content hash before every change. No more stale-line edits.
 - Todo Continuation Enforcer: Forces the agent to continue if it quits halfway. **This is what keeps Sisyphus rolling that boulder.**
 - Comment Checker: Prevents AI from adding excessive comments. Code generated by Sisyphus should be indistinguishable from human-written code.
 - Claude Code Compatibility: Command, Agent, Skill, MCP, Hook(PreToolUse, PostToolUse, UserPromptSubmit, Stop)
@@ -287,6 +288,7 @@ See the full [Features Documentation](docs/features.md) for detailed information
 - **Agents**: Sisyphus (the main agent), Prometheus (planner), Oracle (architecture/debugging), Librarian (docs/code search), Explore (fast codebase grep), Multimodal Looker
 - **Background Agents**: Run multiple agents in parallel like a real dev team
 - **LSP & AST Tools**: Refactoring, rename, diagnostics, AST-aware code search
+- **Hash-anchored Edit Tool**: `LINE#ID` references validate content before applying every change — surgical edits, zero stale-line errors
 - **Context Injection**: Auto-inject AGENTS.md, README.md, conditional rules
 - **Claude Code Compatibility**: Full hook system, commands, skills, agents, MCPs
 - **Built-in MCPs**: websearch (Exa), context7 (docs), grep_app (GitHub search)