budget note command and handler with Feature: Add Note to Budget CommandCQRS pattern

[Emannuh]

Feature: Add Note to Budget Command

How I understand the backend development process & design choices:

• Followed the existing CQRS pattern in the codebase for separation of concerns
• The AddNoteToBudgetCommand is a simple data container following the command pattern
• The AddNoteToBudgetHandler contains the business logic, validation, and data access
• Used dependency injection through the handler's tools parameter for repository access
• Implemented basic validation to ensure data integrity

Deployment approach:
Based on the repo's architecture using @ngfire/functions, this handler would be deployed as a Firebase Cloud Function. The Nx monorepo would compile this library and include it in the functions deployment package.

Serverless deployment knowledge:
Serverless architecture means the cloud provider dynamically manages infrastructure. This handler would:

• Scale automatically with incoming requests
• Launch new instances as needed for concurrent requests
• Only consume resources when actively processing commands
• Provide built-in high availability and fault tolerance
• Follow pay-per-use pricing model