Fix command-line argument passing to pre-fill UI

When running the inspector with command-line arguments (e.g.,
`npx @modelcontextprotocol/inspector node build/index.js arg1 arg2`),
the command and arguments were not being properly passed through to
the UI for pre-filling.

Changes:
- cli.ts now passes command and args to start.js
- start.js uses --command for the command and --args for arguments
- Server parses the new --command parameter
- /config endpoint returns correct values for UI pre-filling

This ensures the UI correctly displays the command and arguments
passed on the command line instead of showing old localStorage values.

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

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

server/src/index.ts

@@ -39,6 +39,7 @@ const { values } = parseArgs({
   options: {
     env: { type: "string", default: "" },
     args: { type: "string", default: "" },
+    command: { type: "string", default: "" },
   },
 });
 
@@ -520,7 +521,7 @@ app.get("/config", originValidationMiddleware, authMiddleware, (req, res) => {
   try {
     res.json({
       defaultEnvironment,
-      defaultCommand: values.env,
+      defaultCommand: values.command,
       defaultArgs: values.args,
     });
   } catch (error) {