Set up async structured JSON logging in analytics microservice

[freddyDOTCMS]

Description

Configure Logback with AsyncAppender and logstash-logback-encoder for structured JSON log output. Apply structured logging across all layers: Controller, Service, Repository.

Every log entry must include standardized fields: customerId, requestId, timestamp, layer, durationMs, endpoint, queryParams, eventType, environment.

The correlation ID must survive the @Async boundary — propagate via AsyncConfig's TaskDecorator, following the same pattern as CustomerContext.

Parent epic: #35048

Acceptance Criteria

• Logback configured with AsyncAppender + logstash-logback-encoder
• All layers (Controller, Service, Repository) emit structured JSON logs
• All standard fields present on every log entry: customerId, requestId, timestamp, layer, durationMs, endpoint, queryParams, eventType, environment
• Correlation ID propagated through @Async boundary via AsyncConfig TaskDecorator

Additional Context

• Source task: Task 6 (Async structured JSON logging) from the improvement plan
• Blocked by: Refactor analytics service ingest code #35050 (ingest code refactor)
• This logging standard is a prerequisite for Task 7 (Fix GlobalExceptionHandler logging)
• Related branch: issue-34849-Add-dotCMS-Analytics-Proxy-Endpoint-for-/v1/analytics/-to-dot-ca-event-manager

[freddyDOTCMS]

PR https://github.com/dotCMS/dot-ca-event-manager/pull/22