Simplify authentication to require URL and API key only

Major configuration and tooling updates:

Authentication Changes:
- Remove username/password authentication support
- Require PORTAINER_URL and PORTAINER_API_KEY (both mandatory)
- Simplify PortainerConfig class and validation logic
- Update all documentation to reflect API key requirement

Multiple Runtime Support:
- Add uvx support for running without installation
- Add uv support with dedicated wrapper script
- Add npx support with Node.js wrapper script
- Maintain backward compatibility with direct Python execution

Documentation Updates:
- Comprehensive README.md with all execution methods
- Detailed USAGE.md with step-by-step instructions
- Updated .env.example with clear required vs optional sections
- Enhanced docstrings in server.py and config.py

Tooling Support:
- package.json for npm/npx support with cross-platform wrapper
- scripts/run-with-uv.py for uv integration
- bin/portainer-core-mcp Node.js wrapper for npx
- test_uvx.py for uvx functionality testing

Configuration Improvements:
- Clear separation of required vs optional environment variables
- Better validation error messages
- Simplified authentication flow
- Enhanced project metadata in pyproject.toml

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

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

bin/portainer-core-mcp

@@ -0,0 +1,115 @@
+#!/usr/bin/env node
+
+const { spawn } = require('child_process');
+const path = require('path');
+
+// Get the directory where this script is located
+const scriptDir = path.dirname(__filename);
+const runServerPath = path.join(scriptDir, '..', 'run_server.py');
+
+// Check if Python is available
+function checkPython() {
+  return new Promise((resolve, reject) => {
+    const pythonCmd = process.platform === 'win32' ? 'python' : 'python3';
+    const proc = spawn(pythonCmd, ['--version'], { stdio: 'pipe' });
+    
+    proc.on('close', (code) => {
+      if (code === 0) {
+        resolve(pythonCmd);
+      } else {
+        // Try alternative python command
+        const altPythonCmd = 'python';
+        const altProc = spawn(altPythonCmd, ['--version'], { stdio: 'pipe' });
+        
+        altProc.on('close', (altCode) => {
+          if (altCode === 0) {
+            resolve(altPythonCmd);
+          } else {
+            reject(new Error('Python is not installed or not in PATH'));
+          }
+        });
+      }
+    });
+  });
+}
+
+// Run the Python server
+async function runServer() {
+  try {
+    const pythonCmd = await checkPython();
+    console.log('🚀 Starting Portainer Core MCP Server via npx...');
+    
+    const proc = spawn(pythonCmd, [runServerPath], { 
+      stdio: 'inherit',
+      cwd: path.dirname(runServerPath)
+    });
+    
+    proc.on('error', (err) => {
+      console.error('❌ Failed to start server:', err.message);
+      process.exit(1);
+    });
+    
+    proc.on('close', (code) => {
+      if (code !== 0) {
+        console.error(`❌ Server exited with code ${code}`);
+        process.exit(code);
+      }
+    });
+    
+    // Handle signals
+    process.on('SIGINT', () => {
+      console.log('\n👋 Stopping server...');
+      proc.kill('SIGINT');
+    });
+    
+    process.on('SIGTERM', () => {
+      console.log('\n👋 Stopping server...');
+      proc.kill('SIGTERM');
+    });
+    
+  } catch (error) {
+    console.error('❌ Error:', error.message);
+    console.error('💡 Please ensure Python 3.8+ is installed and in your PATH');
+    process.exit(1);
+  }
+}
+
+// Show help
+function showHelp() {
+  console.log(`
+Portainer Core MCP Server
+
+Usage:
+  npx portainer-core-mcp [options]
+
+Options:
+  -h, --help     Show this help message
+  -v, --version  Show version information
+
+Environment Variables:
+  PORTAINER_URL      Portainer instance URL (required)
+  PORTAINER_API_KEY  Portainer API key (required)
+  LOG_LEVEL          Logging level (default: INFO)
+  DEBUG              Enable debug mode (default: false)
+
+Examples:
+  npx portainer-core-mcp
+  PORTAINER_URL=https://portainer.example.com PORTAINER_API_KEY=your-key npx portainer-core-mcp
+`);
+}
+
+// Main
+const args = process.argv.slice(2);
+
+if (args.includes('-h') || args.includes('--help')) {
+  showHelp();
+  process.exit(0);
+}
+
+if (args.includes('-v') || args.includes('--version')) {
+  const packageJson = require('../package.json');
+  console.log(`portainer-core-mcp v${packageJson.version}`);
+  process.exit(0);
+}
+
+runServer().catch(console.error);