refactor(e2e): migrate remaining tests to TestContainer abstraction

[rgarcia]

Summary

• Migrate all tests in e2e_chromium_test.go from the old manual docker exec pattern to the TestContainer abstraction
• Remove old helper functions (runContainer, stopContainer, waitHTTPOrExit, etc.)
• Use NewTestContainer/Start/Stop pattern with dynamic port allocation
• Update execCombinedOutput and helper functions to accept *TestContainer
• Add t.Parallel() to all tests for parallel execution
• Update logCDPDiagnostics in e2e_combined_flow_test.go for new signature

This enables parallel test execution and removes ~300 lines of duplicate container management code. All e2e tests now consistently use the TestContainer abstraction.

Tests migrated

• TestDisplayResolutionChange
• TestExtensionUploadAndActivation
• TestScreenshotHeadless
• TestScreenshotHeadful
• TestInputEndpointsSmoke
• TestCDPTargetCreation
• TestWebBotAuthInstallation

Test plan

• CI passes
• E2E tests execute successfully in parallel

Made with Cursor

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Note

Medium Risk
Medium risk because it refactors test harness/container lifecycle and enables t.Parallel() across Docker-backed E2E tests, which can surface port allocation, readiness, or race-condition issues without changing production code.

Overview
Refactors e2e_chromium_test.go to run all Chromium E2E scenarios via the TestContainer abstraction (dynamic ports + WaitReady/WaitDevTools) instead of hard-coded docker run/kill/wait helpers, and removes the old container-management utilities.

Enables parallel execution for these E2E tests (t.Parallel()), updates remote exec helpers (execCombinedOutput, getXvfbResolution, listCDPTargets) to take *TestContainer, and adjusts the combined-flow diagnostics helper (logCDPDiagnostics) to exec inside the specific test container.

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