[demo split #4449] 3/5 — Extend e2e framework for the debugger package

[allspain]

DEMO — split of #4449. This is one of 5 stacked draft PRs that breaks
#4449 — Add Live Debugger package
into reviewable increments. Original PR is untouched. This stack is for
demonstrating tooling (jj split for the surgery, gh for the stack);
all of the underlying code is Thomas Watson's work and credited via
Co-authored-by: trailers.

Stack

1. [demo split #4449] 1/5 — Foundation: expose core hooks for the live debugger package #4532 — Foundation — expose core hooks for the live debugger package (12 files / +56-10)
2. [demo split #4449] 2/5 — Add @datadog/browser-debugger package #4533 — Package — add @datadog/browser-debugger (25 files / +6433)
3. [demo split #4449] 3/5 — Extend e2e framework for the debugger package #4534 — E2E framework — extend test framework for the debugger package (12 files / +129-8) ← you are here
4. [demo split #4449] 4/5 — Add debugger e2e scenarios #4535 — E2E scenarios — add debugger e2e scenarios (3 files / +318-2)
5. [demo split #4449] 5/5 — Add instrumentation overhead benchmarks #4536 — Perf benchmarks — add instrumentation overhead benchmarks (12 files / +1222-9)

Each PR's base branch is the previous PR's head, so reviewing in order is
the intended path. Stack constructed with jj:
all 4 commits from #4449 were squashed into one change, then peeled into 5
with jj split <paths>, then pushed with jj git push.

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What this PR contains (3/5 — E2E framework)

E2E framework + build-tooling extensions so subsequent PRs in the stack can
write debugger scenarios and benchmarks. No actual scenarios yet — those
land in PR 4.

Changes

• test/e2e/lib/framework
  • createTest.ts — adds .withDebugger() builder method.
  • intakeRegistry.ts — adds DebuggerIntakeRequest type and
    intakeRegistry.debuggerEvents.
  • pageSetups.ts — debugger page setups for CDN/bundle/npm modes.
  • httpServers.ts, intakeProxyMiddleware.ts, serverApps/mock.ts,
    helpers/configuration.ts, lib/types/global.ts, index.ts — wiring.
• Tooling
  • scripts/build/build-test-apps.ts — use resolution paths when
    installing peer deps so unpublished packages (only present locally as
    .tgz) work.
  • scripts/dev-server/lib/server.ts — serve the debugger bundle.
  • test/apps/.gitignore — ignore the new instrumentation test app's
    build artefacts (used by PR 5).

12 files, +129 / -8.

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[datadog-datadog-prod-us1-2]

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 76.67% (-0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 86854b8 | Docs | Datadog PR Page | Give us feedback!}

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	N/A	179.42 KiB	N/A	N/A	N/A
Rum Profiler	N/A	6.16 KiB	N/A	N/A	N/A
Rum Recorder	N/A	27.03 KiB	N/A	N/A	N/A
Logs	N/A	56.80 KiB	N/A	N/A	N/A
Rum Slim	N/A	135.26 KiB	N/A	N/A	N/A
Worker	N/A	23.63 KiB	N/A	N/A	N/A

🚀 CPU Performance

Pending...

🧠 Memory Performance

Pending...

🔗 RealWorld