refactor: move browser auto-open logic to client process

Simplifies the startup flow by consolidating browser opening
in the client script rather than the start script for prod.

We were duplicating a lot of logging, making it easy for
logs to go out of sync - this is a proposal to consolidate:

- server only logs info about itself
- client only logs info about itself

To reduce the number of places we print connection information
to the user.

client/bin/client.js

@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+import open from "open";
 import { join, dirname } from "path";
 import { fileURLToPath } from "url";
 import handler from "serve-handler";
@@ -42,9 +43,12 @@ const server = http.createServer((request, response) => {
 const port = parseInt(process.env.CLIENT_PORT || "6274", 10);
 const host = process.env.HOST || "localhost";
 server.on("listening", () => {
-  console.log(
-    `🔍 MCP Inspector is up and running at http://${host}:${port} 🚀`,
-  );
+  const url = process.env.INSPECTOR_URL || `http://${host}:${port}`;
+  console.log(`\n🚀 MCP Inspector is up and running at:\n   ${url}\n`);
+  if (process.env.MCP_AUTO_OPEN_ENABLED !== "false") {
+    console.log(`🌐 Opening browser...`);
+    open(url);
+  }
 });
 server.on("error", (err) => {
   if (err.message.includes(`EADDRINUSE`)) {

client/bin/start.js

@@ -187,17 +187,12 @@ async function startProdClient(clientOptions) {
     SERVER_PORT,
   );
 
-  // Handle auto-open and logging
-  if (!cancelled) {
-    console.log(`\n🚀 MCP Inspector is up and running at:\n   ${url}\n`);
-    if (process.env.MCP_AUTO_OPEN_ENABLED !== "false") {
-      console.log(`\n🌐 Opening browser...:\n`);
-      open(url);
-    }
-  }
-
   await spawnPromise("node", [inspectorClientPath], {
-    env: { ...process.env, CLIENT_PORT: CLIENT_PORT },
+    env: {
+      ...process.env,
+      CLIENT_PORT: CLIENT_PORT,
+      INSPECTOR_URL: url,
+    },
     signal: abort.signal,
     echoOutput: true,
   });