CCM-14199 - Foundational: Infrastructure as Code and Core Types

[mjewildnhs]

Description

This PR establishes the foundational infrastructure and core type definitions for the NHS Notify Client Callbacks system. It includes:

• Terraform Infrastructure: S3 bucket for client configuration storage
• TypeScript Type System: Comprehensive type definitions for status events, callback payloads, and client configuration
• Development Tooling: Updated ESLint configuration, Jest setup, Sonar scanner properties, and pre-commit hooks

Context

This work is part of CCM-14199 and lays the groundwork for externalizing client callbacks from the main Communications Manager system. The foundational infrastructure enables:

1. Receiving status transition events from the internal EventBus
2. Transforming and filtering events based on client-specific subscriptions
3. Delivering callbacks to client webhooks with appropriate rate limiting

This foundation will be built upon in subsequent phases to add full transformation logic, error handling, DLQs, and monitoring.

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming
• If I have used the 'skip-trivy-package' label I have done so responsibly and in the knowledge that this is being fixed as part of a separate ticket/PR.

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Sensitive Information Declaration

To ensure the utmost confidentiality and protect your and others privacy, we kindly ask you to NOT including PII (Personal Identifiable Information) / PID (Personal Identifiable Data) or any other sensitive data in this PR (Pull Request) and the codebase changes. We will remove any PR that do contain any sensitive information. We really appreciate your cooperation in this matter.

• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud

[rhyscoxnhs]

LGTM

[cgitim]

REFCOM changes :(