docs(event-handler): add http router decorator examples

[matthew2564]

Summary

I was looking into using the new Event Handler utility, but specifically with decorators. This PR adds documentation and examples for HTTP Router decorators in the Event Handler utility. The decorator syntax was fully implemented but completely undocumented - this fills that documentation gap.

Changes

Documentation (docs/features/event-handler/http.md):

• Added "Using decorators" section after HTTP Methods with basic decorator examples
• Added decorator examples for error handling (@app.errorHandler())
• Added decorator examples for built-in error handlers (@app.notFound(), @app.methodNotAllowed())

Example Files (4 new files in examples/snippets/event-handler/http/):

• gettingStarted_decorators_basic.ts - Basic route handler decorators
• gettingStarted_error_handling_decorators.ts - Error handler decorators
• gettingStarted_built_in_error_handler_decorators.ts - Built-in error handler decorators
• advanced_mw_middleware_order_decorators.ts - Middleware with decorators

Coverage:

• ✅ All HTTP method decorators (@app.get(), @app.post(), @app.put(), etc)
• ✅ Custom error handlers with @app.errorHandler(ErrorClass)
• ✅ Built-in error handlers (@app.notFound(), @app.methodNotAllowed())
• ✅ Scope preservation with { scope: this }

Issue number: closes #4951

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[boring-cyborg]

Thanks a lot for your first contribution! Please check out our contributing guidelines and don't hesitate to ask whatever you need.
In the meantime, check out the #typescript channel on our Powertools for AWS Lambda Discord: Invite link

[svozza]

Have added a few comments. Something I noticed is that a lot the highlighting in the code examples was off by one or two lines. If you do npm run docs:local:setup followed by docs:local:run you will be able to view your docs on http://127.0.0.1:8000/powertools/typescript/latest/features/event-handler/http to verifiy that they look correct.

Route method is not a decorator

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
13.2% Duplication on New Code

See analysis details on SonarQube Cloud

[svozza]

Thank you @matthew2564 for your work on this! Merging now.

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!

[github-actions]

@aws-powertools/lambda-typescript No related issues found. Please ensure 'pending-release' label is applied before releasing.