refactor: major cleanup of legacy and temporary files

- Removed ~965MB of temporary directories (temp/, extracted-nodes/, etc)
- Deleted outdated database files and backups (.bak files)
- Removed legacy shell scripts (mcp-server-v20.sh, rebuild-v20.sh)
- Cleaned up orphan test files and debugging scripts
- Removed duplicate schema file (src/db/schema.sql)
- Deleted old Dockerfile.old and empty database files
- Updated documentation structure in README.md
- Added n8n_diagnostic tool to documentation
- Condensed version history in CLAUDE.md
- Created release notes for v2.7.0

Total impact: Removed 34 files, saving ~965MB+ of disk space

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

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

release-notes-v2.7.0.md

@@ -0,0 +1,60 @@
+# n8n-MCP v2.7.0 Release Notes
+
+## 🎉 What's New
+
+### 🔧 File Refactoring & Version Management
+- **Renamed core MCP files** to remove unnecessary suffixes for cleaner codebase:
+  - `tools-update.ts` → `tools.ts`
+  - `server-update.ts` → `server.ts`
+  - `http-server-fixed.ts` → `http-server.ts`
+- **Fixed version management** - Now reads from package.json as single source of truth (fixes #5)
+- **Updated imports** across 21+ files to use the new file names
+
+### 🔍 New Diagnostic Tool
+- **Added `n8n_diagnostic` tool** - Helps troubleshoot why n8n management tools might not be appearing
+- Shows environment variable status, API connectivity, and tool availability
+- Provides step-by-step troubleshooting guidance
+- Includes verbose mode for additional debug information
+
+### 🧹 Code Cleanup
+- Removed legacy HTTP server implementation with known issues
+- Removed unused legacy API client
+- Added version utility for consistent version handling
+- Added script to sync runtime package version
+
+## 📦 Installation
+
+### Docker (Recommended)
+```bash
+docker pull ghcr.io/czlonkowski/n8n-mcp:2.7.0
+```
+
+### Claude Desktop
+Update your configuration to use the latest version:
+```json
+{
+  "mcpServers": {
+    "n8n-mcp": {
+      "command": "docker",
+      "args": ["run", "-i", "--rm", "ghcr.io/czlonkowski/n8n-mcp:2.7.0"]
+    }
+  }
+}
+```
+
+## 🐛 Bug Fixes
+- Fixed version mismatch where version was hardcoded as 2.4.1 instead of reading from package.json
+- Improved error messages for better debugging
+
+## 📚 Documentation Updates
+- Condensed version history in CLAUDE.md
+- Updated documentation structure in README.md
+- Removed outdated documentation files
+- Added n8n_diagnostic tool to documentation
+
+## 🙏 Acknowledgments
+Thanks to all contributors and users who reported issues!
+
+---
+
+**Full Changelog**: https://github.com/czlonkowski/n8n-mcp/blob/main/CHANGELOG.md