Port browser-integration-tests to span streaming

Port `dev-packages/browser-integration-tests` to span streaming. Span streaming is the default, so every suite that still pins `traceLifecycle: 'static'` covers behaviour we no longer ship.

Part of [SDK-1425](https://linear.app/getsentry/issue/SDK-1425/port-integration-tests-to-span-streaming), one tracking issue per integration test package.

## Scope

* 315 `traceLifecycle: 'static'` pins across 299 files
* 62 `test.ts` files call `waitForTransactionRequest` and need a real rewrite
* 36 suites already have a `-streamed` twin, and 32 of those still sit next to the static original
* The remaining ~226 pinned files never assert on a transaction, so they only need the pin removed

## How to port a suite

1. Remove the `traceLifecycle: 'static'` pin from the suite's `init.js` (and any subtest init).
2. If a `-streamed` twin exists, fold it back: delete the static original and rename the twin to the base name. Do not keep both, or the coverage doubles and the two copies drift.
3. Rewrite the assertions from transaction envelopes to span v2 using `utils/spanUtils.ts`:
* `waitForTransactionRequest` becomes `waitForStreamedSpan` / `waitForStreamedSpans`
* `waitForStreamedSpanEnvelope` gives the raw envelope when a test asserts on envelope headers
* `event.transaction` becomes `span.name`
* `contexts.trace.op` becomes the `sentry.op` attribute 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
4. Streamed child spans arrive across several envelopes, so collect across envelopes wherever a test asserts on children of a segment span.

Watch for span names that become low cardinality under streaming: pageload, navigation, resource, `http.client` and web vitals. Those assertions change, not just the helper.

## Keep static trace lifecycle coverage

Do not add a `-static` copy per suite. The `profiling/traceLifecycleMode_*` suites already exercise both lifecycles. Pick one tracing suite to keep on the static pin as a guard and say so in the PR.