Populate trace_ids in mobile replay events to enable searching replays by trace ID #6232

Problem

When searching for replays by trace ID in Sentry's Explore UI, mobile replays from React Native are not discoverable. While web replay (via JS SDK) collects trace_ids, the mobile replay integration does not.

Solution

The mobileReplayIntegration should collect trace IDs when transactions are captured and pass them to the native replay system.

Reference implementations

• JS (web replay): https://github.com/getsentry/sentry-javascript/blob/30eb68fff5077211c30c61ba74625e66ab514870/packages/replay-internal/src/coreHandlers/handleAfterSendEvent.ts#L34-L43
• Java (Android native): fix(replay): Associate trace IDs with replay segments sentry-java#5473

Key points

• Collect trace IDs when transactions are successfully captured during replay recording
• Limit to max 100 trace IDs per segment (matching JS SDK)
• Need a bridge mechanism to pass trace IDs from JS transactions to native replay
• Android native SDK (sentry-java) now supports registerTraceId() — need similar support in iOS (sentry-cocoa)

Dependencies

• sentry-cocoa needs to implement trace_ids support first (or in parallel)

Action taken on behalf of Roman Zavarnitsyn.