fix: update serve:http to run main.ts instead of server.ts (#315)

After commit 65a62a9f, the server startup code was moved from server.ts
to main.ts, but the serve:http script was not updated accordingly.

This caused 9 example servers to fail to start when running npm start:
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- integration-server
- map-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- wiki-explorer-server

The server.ts file now only exports createServer(), while main.ts
contains the actual server startup logic.

examples/scenario-modeler-server/package.json

@@ -16,7 +16,7 @@
   "scripts": {
     "build": "tsc --noEmit && cross-env INPUT=mcp-app.html vite build && tsc -p tsconfig.server.json && bun build server.ts --outdir dist --target node && bun build main.ts --outfile dist/index.js --target node --external \"./server.js\" --banner \"#!/usr/bin/env node\"",
     "watch": "cross-env INPUT=mcp-app.html vite build --watch",
-    "serve:http": "bun --watch server.ts",
+    "serve:http": "bun --watch main.ts",
     "serve:stdio": "bun server.ts --stdio",
     "start": "npm run start:http",
     "start:http": "cross-env NODE_ENV=development npm run build && npm run serve:http",