fix(browser): simplify orchestrator otel carrier

[hi-ogawa]

Description

• Related feat: support openTelemetry for browser mode #9180

It looks like I had a weird indirection to propagate otelCarrier to orchestrator #9180.

Previously it did:

• browser pool opens ?otelCarrier=... as orchestrator page (along with ?sessionId=...)
• orchestrator page middleware then extract ?otelCarrier from request, which then inject back to shell html

This now becomes:

• browser pool open orchestrator page as usual ?sessionId=.... we record otelCarrier on server side session object.
• orchestrator page middleware then picks up otelCarrier associated with sessionId on the server side.

How to test

Manually verified running examples/opentelemetry

screenshot

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[hi-ogawa]

Opening /__vitest_test__/ without ?sessionId is allowed for preview, but for otelCarrier, it's legitimate to require proper sessionId -> session mapping on server side.

[hi-ogawa]

To be honest, I have no idea how sessionId-less orchestrator is meant to work. Probably we should revisit the proper invariant around these fallback.

[sheremet-va]

I think it just picks up the first available one

[Copilot]

Pull request overview

This PR refactors how OpenTelemetry context (otelCarrier) is propagated to the browser orchestrator, switching from URL query parameter propagation to server-side session storage keyed by sessionId.

Changes:

• Store otelCarrier on the server-side browser session object when creating a browser session.
• Stop appending otelCarrier to the orchestrator URL query parameters.
• Inject __VITEST_OTEL_CARRIER__ into orchestrator HTML from the server-side session instead of url.searchParams.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
packages/vitest/src/node/types/browser.ts	Extends BrowserServerStateSession to optionally include otelCarrier.
packages/vitest/src/node/project.ts	Stops adding otelCarrier to the orchestrator URL; passes it into session creation instead.
packages/vitest/src/node/browser/sessions.ts	Adds optional otelCarrier to the created session record via createSession options.
packages/browser/src/node/serverOrchestrator.ts	Reads otelCarrier from the server-side session and injects it into the orchestrator client payload.