fix: cleanup stale references and update tests after tool removal

- Remove handleListAvailableTools dead code from handlers-n8n-manager.ts
- Update error messages to reference n8n_health_check(mode="diagnostic") instead of n8n_diagnostic
- Update tool counts in diagnostic messages (14 doc tools, 31 total)
- Fix error-handling.test.ts to use valid tools (search_nodes, tools_documentation)
- Remove obsolete list-tools.test.ts integration tests
- Remove unused ListToolsResponse type from response-types.ts
- Update tools.ts QUICK REFERENCE to remove list_nodes references
- Update tools-documentation.ts to remove references to removed tools
- Update tool-docs files to remove stale relatedTools references
- Fix tools.test.ts to not test removed tools (list_nodes, list_ai_tools, etc.)
- Fix parameter-validation.test.ts to not test removed tools
- Update handlers-n8n-manager.test.ts error message expectations

All 399 MCP unit tests now pass.

Conceived by Romuald Członkowski - www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/agents/code-reviewer.md

@@ -1,6 +1,7 @@
 ---
 name: code-reviewer
 description: Use this agent when you need to review recently written or modified code for quality, security, and maintainability. This agent should be invoked immediately after code changes are made to ensure high standards are maintained. Examples:\n\n<example>\nContext: The user has created a code-review agent that should be called after writing code.\nuser: "Please write a function that validates email addresses"\nassistant: "I'll create an email validation function for you:"\n<function implementation>\nassistant: "Now let me use the code-reviewer agent to review this code for quality and security"\n<commentary>\nSince new code was just written, the code-reviewer agent should be invoked to ensure it meets quality standards.\n</commentary>\n</example>\n\n<example>\nContext: The user has modified existing code and wants it reviewed.\nuser: "I've updated the authentication logic, can you check if it's secure?"\nassistant: "I'll use the code-reviewer agent to analyze your authentication changes for security and best practices"\n<commentary>\nThe user has made changes to security-critical code, so the code-reviewer agent is the appropriate tool to ensure the modifications are secure and well-implemented.\n</commentary>\n</example>
+model: inherit
 ---
 
 You are a senior code reviewer with extensive experience in software engineering, security, and best practices. Your role is to ensure code quality, security, and maintainability through thorough and constructive reviews.