refactor: clean up file names and fix version management

- Renamed files to remove unnecessary suffixes:
  - tools-update.ts → tools.ts
  - server-update.ts → server.ts
  - http-server-fixed.ts → http-server.ts
- Created version utility to read from package.json as single source of truth
- Updated all imports across 21+ files
- Removed legacy files:
  - src/http-server.ts (legacy HTTP server with known issues)
  - src/utils/n8n-client.ts (unused legacy API client)
- Added n8n_diagnostic tool to help troubleshoot management tools visibility
- Added script to sync package.runtime.json version
- Fixed version mismatch issue (was hardcoded 2.4.1, now reads 2.7.0 from package.json)

This addresses GitHub issue #5 regarding version mismatch and provides better diagnostics for users.

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

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

scripts/sync-runtime-version.js

@@ -0,0 +1,40 @@
+#!/usr/bin/env node
+
+/**
+ * Sync version from package.json to package.runtime.json
+ * This ensures both files always have the same version
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+const packageJsonPath = path.join(__dirname, '..', 'package.json');
+const packageRuntimePath = path.join(__dirname, '..', 'package.runtime.json');
+
+try {
+  // Read package.json
+  const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, 'utf-8'));
+  const version = packageJson.version;
+  
+  // Read package.runtime.json
+  const packageRuntime = JSON.parse(fs.readFileSync(packageRuntimePath, 'utf-8'));
+  
+  // Update version if different
+  if (packageRuntime.version !== version) {
+    packageRuntime.version = version;
+    
+    // Write back with proper formatting
+    fs.writeFileSync(
+      packageRuntimePath, 
+      JSON.stringify(packageRuntime, null, 2) + '\n',
+      'utf-8'
+    );
+    
+    console.log(`✅ Updated package.runtime.json version to ${version}`);
+  } else {
+    console.log(`✓ package.runtime.json already at version ${version}`);
+  }
+} catch (error) {
+  console.error('❌ Error syncing version:', error.message);
+  process.exit(1);
+}