Port React Router E2E test apps to span streaming #23798

Port these E2E test applications to span streaming (17 apps).

Apps

• react-create-browser-router
• react-create-hash-router
• react-create-memory-router
• react-router-5
• react-router-6
• react-router-6-descendant-routes
• react-router-6-use-routes
• react-router-7-cross-usage
• react-router-7-framework
• react-router-7-framework-instrumentation
• react-router-7-framework-spa
• react-router-7-lazy-routes
• react-router-7-spa
• react-router-8-cloudflare
• react-router-8-cross-usage
• react-router-8-framework
• react-router-8-spa

What to do

For each app:

1. Remove the traceLifecycle: 'static' pin added in test(e2e): Disable span streaming in e2e test applications #22590 from every Sentry.init (client, server, edge).
2. Rewrite the specs from transaction envelopes to span v2:
   • waitForTransaction becomes waitForStreamedSpan / waitForStreamedSpans
   • event.transaction becomes span.name
   • contexts.trace.op becomes getSpanOp(span) plus span.is_segment
   • contexts.trace.data['x'] becomes span.attributes['x'], which has the shape { value, type }
   • transaction_info.source becomes the sentry.segment.name.source attribute
3. Streamed child spans arrive across several envelopes, so use collectStreamedSpans wherever a test asserts on children of a segment span.

Watch for span names that become low cardinality under streaming (Pageload, Navigation, Router, HTTP, and so on). Those assertions have to change, not just the helper.

Reference apps: react-router-7-spa-streaming and nextjs-16-streaming. Worked example: #23797.

Keep static trace lifecycle coverage

Before porting this group, duplicate react-router-7-framework as-is into react-router-7-framework-static and leave that copy on the current transaction-based specs. That keeps the static trace lifecycle covered once the rest of the group moves to streaming.

The copy is verbatim; only the app name changes:

• package.json -> name
• start-event-proxy.mjs -> proxyServerName
• every waitForTransaction / waitForError / waitForSession call in tests/

Keep traceLifecycle: 'static' in the copy's Sentry.init calls. The e2e matrix discovers apps by directory, so no CI config change is needed.

The representative is a suggestion: swap it if another app in the list exercises more of this SDK's instrumentation.