Update devDependencies: @types/node 20→22, TypeScript 4→5

## Summary

Update TypeScript MCP template devDependencies to match Node.js 22 runtime.

## Current State

**package.json:**
```json
{
"dependencies": {
"@azure/functions": "4.12.0-preview.2",
"zod": "^3.24.2"
},
"devDependencies": {
"@types/node": "^20.x",
"rimraf": "^5.0.0",
"typescript": "^4.0.0"
},
"main": "dist/src/index.js"
}
```

**infra/main.bicep:** Node 22 ✅ (already current)

## Proposed Changes

**package.json:**
```json
{
"devDependencies": {
"@types/node": "^22.x",
"rimraf": "^5.0.0",
"typescript": "^5.0.0"
}
}
```

## Why These Changes?

| Change | Reason |
|--------|--------|
| `@types/node` 20→22 | Type definitions should match runtime version (Node 22) |
| `typescript` 4→5 | Latest stable with better performance and features |

## Testing Checklist

- [ ] `npm install` succeeds
- [ ] `npm run build` compiles without errors
- [ ] `func start` discovers all MCP tools
- [ ] `azd up` deploys successfully
- [ ] MCP tools respond correctly via HTTP transport

Update the devDependencies in package.json while keeping infra/main.bicep's Node 22 runtime aligned. Start with npm install, then run npm run build, func start, and azd up; done means installation, compilation, tool discovery, deployment, and HTTP MCP responses all succeed.

Written by the indexing model from the issue text.