test(web): add Stovepipe coverage and align E2E suites

[mnoah1]

Why?

The new Stovepipe UI needs browser coverage against a real backend, in addition to its unit and component tests. Align both services' browser suites under web/test/e2e/<domain> so they follow the repository layout and reuse stack setup helpers.

What?

• Move the existing SubmitQueue browser suite into web/test/e2e/submitqueue, preserving its browser spec and Compose overlay.
• Add web/test/e2e/stovepipe with real ingestion and seeded pagination data. Cover queue navigation and cursors, request-ID links and reloads, backend status summaries above history, refresh, empty queues, and accessibility. A summary with a newer state than the history verifies that the UI does not reconstruct status from events.
• Share image loading, schema application, and port lookup helpers. Both browser runners use the Bazel-pinned Compose executable from chore(docker): supply docker compose via Bazel #830.
• Update Bazel targets and visibility, workspace entries, runner commands, and test documentation for the new layout. Tests emit queue and request-page screenshots as Bazel test outputs.

Test Plan

Latest validation passed all 32 targets, including both services' real-stack browser suites:

./tool/bazel test //web:check //web/test/e2e/submitqueue:web_test //web/test/e2e/stovepipe:web_test --test_output=errors

Repository formatting, lint, module tidy, and Gazelle checks also passed. Browser tests require a running Docker daemon; Bazel supplies Compose and the browser.

Stack

1. refactor(web): extract shared UI and host packages #842 — shared-package refactoring
2. feat(web): add Stovepipe request status UI #837 — Stovepipe frontend
3. test(web): add Stovepipe coverage and align E2E suites #838 — browser coverage and E2E organization
4. refactor(web): let hosts handle request logging #844 — host logging integration