Integrate and Configure Helm Subcharts

[asadaaron]

Description

Add and configure required and optional subcharts for dependencies.

Tasks

• Integrate Valkey (enabled by default)
• Integrate PostgreSQL (conditional, supports external secret)
• Integrate OpenTelemetry Collector (conditional)
• Configure connection details exposure to app components

Acceptance Criteria

• Subcharts deploy correctly when enabled
• Application connects to dependencies
• Disabling subcharts works with external services