Cross-connector duplicate Kafka event E2E test

[askmy-stack]

Background

Identified during OSS audit v2 of cortex.

Problem Statement

Dedup not E2E tested.

Proposed Solution

Publish same event_id twice.

Acceptance Criteria

• Implementation complete
• Tests pass
• Documented in README or docs/

Files / Modules Affected

tests/integration/

---

Suggested labels: priority:medium, difficulty:advanced, category:testing
Milestone: v2.0-features
OSS Audit: Master Backlog v2