docs: add cleanup command to README

- Add step 7 for cleanup in quick start guide
- Add cleanup to core commands table
- Add detailed step 8 in walkthrough section explaining:
  - Small/medium/large issue handling
  - Output artifacts (fixes, tasks, tech-debt-report.md)
  - Critical issue halt behavior

Author: dsrednicki

README.md

@@ -132,6 +132,14 @@ Use **`/speckit.implement`** to execute all tasks and build your feature accordi
 /speckit.implement
 ```
 
+### 7. Review and clean up
+
+Use **`/speckit.cleanup`** to review all implementation changes, identify tech debt, and ensure code quality.
+
+```bash
+/speckit.cleanup
+```
+
 For detailed step-by-step instructions, see our [comprehensive guide](./spec-driven.md).
 
 ## 📽️ Video Overview
@@ -258,6 +266,7 @@ Essential commands for the Spec-Driven Development workflow:
 | `/speckit.plan`         | Create technical implementation plans with your chosen tech stack        |
 | `/speckit.tasks`        | Generate actionable task lists for implementation                        |
 | `/speckit.implement`    | Execute all tasks to build the feature according to the plan             |
+| `/speckit.cleanup`      | Review implementation, fix small issues, identify tech debt              |
 
 #### Optional Commands
 
@@ -614,6 +623,30 @@ The `/speckit.implement` command will:
 
 Once the implementation is complete, test the application and resolve any runtime errors that may not be visible in CLI logs (e.g., browser console errors). You can copy and paste such errors back to your AI agent for resolution.
 
+### **STEP 8:** Clean up and review
+
+After implementation is complete, use the `/speckit.cleanup` command to perform a final quality review:
+
+```text
+/speckit.cleanup
+```
+
+The `/speckit.cleanup` command will:
+
+- Review all files modified during implementation
+- **Fix small issues immediately** (Scout Rule): Remove debugging artifacts (console.log, print statements), unused imports, dead code, and other mechanical issues
+- **Create follow-up tasks** for medium issues: Missing error handling, code duplication, incomplete documentation
+- **Generate detailed analysis** for large issues: Architectural concerns, security vulnerabilities, performance bottlenecks - each with multiple options and recommendations
+
+The cleanup phase produces:
+
+- **Direct fixes** committed with clear messages for small issues
+- **Tech Debt Tasks section** appended to `tasks.md` for medium issues (can be addressed by re-running `/speckit.implement`)
+- **`tech-debt-report.md`** for large issues requiring team discussion, with problem descriptions, impact assessments, and recommended approaches
+
+> [!NOTE]
+> The cleanup command will halt on critical security issues (hardcoded credentials, exposed secrets) and require you to fix them before proceeding.
+
 </details>
 
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