Update server-everything to allow choosing the transport on the command line.

# Run the default (stdio) server
```npx @modelcontextprotocol/server-everything```

# Or specify stdio explicitly
```npx @modelcontextprotocol/server-everything stdio```

# Run the SSE server
```npx @modelcontextprotocol/server-everything sse```

# Run the streamable HTTP server
```npx @modelcontextprotocol/server-everything streamableHttp```

* In src/everything/index.ts
  - refactor/extracted contents to stdio.ts
  - replaced with code that
    - Gets the single argument from the commandline as scriptName
    - switches on scriptName
    - imports the appropriate server script or outputs usage options
  - scripts run on import

* In src/everything/stdio.ts
  - added console log "Starting default (STDIO) server..."

* In src/everything/sse.ts
  - added console log "Starting SSE server..."

* In src/everything/streamableHttp.ts
  - added console log "Starting Streamable HTTP server..."

* This fixes #1594

src/everything/index.ts

@@ -1,23 +1,37 @@
 #!/usr/bin/env node
 
-import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
-import { createServer } from "./everything.js";
+// Parse command line arguments first
+const args = process.argv.slice(2);
+const scriptName = args[0] || 'stdio';
 
-async function main() {
-  const transport = new StdioServerTransport();
-  const { server, cleanup } = createServer();
-
-  await server.connect(transport);
-
-  // Cleanup on exit
-  process.on("SIGINT", async () => {
-    await cleanup();
-    await server.close();
-    process.exit(0);
-  });
+async function run() {
+    try {
+        // Dynamically import only the requested module to prevent all modules from initializing
+        switch (scriptName) {
+            case 'stdio':
+                // Import and run the default server
+                await import('./stdio.js');
+                break;
+            case 'sse':
+                // Import and run the SSE server
+                await import('./sse.js');
+                break;
+            case 'streamableHttp':
+                // Import and run the streamable HTTP server
+                await import('./streamableHttp.js');
+                break;
+            default:
+                console.error(`Unknown script: ${scriptName}`);
+                console.log('Available scripts:');
+                console.log('- stdio');
+                console.log('- sse');
+                console.log('- streamableHttp');
+                process.exit(1);
+        }
+    } catch (error) {
+        console.error('Error running script:', error);
+        process.exit(1);
+    }
 }
 
-main().catch((error) => {
-  console.error("Server error:", error);
-  process.exit(1);
-});
+run();