test: cover waitforhelper network multiplier and navigation paths

[ZayanKhan-12]

Why

tests/WaitForHelper.test.ts currently only covers dialog handling. The exported pure function getNetworkMultiplierFromString (src/WaitForHelper.ts) had no coverage at all, and the navigation/timeout paths of waitForEventsAfterAction were untested. This PR expands the test file to lock in the current behavior of those paths. No src/ changes.

Coverage added

• getNetworkMultiplierFromString: exact multipliers for each predefined condition (Fast 4G → 1, Slow 4G → 2.5, Fast 3G → 5, Slow 3G → 10), fallback to 1 for unknown strings and for null.
• Cross-document navigation: an action that navigates resolves with navigatedToUrl set to the destination.
• No navigation: resolves quickly (bounded well below #stableDomTimeout) with no navigatedToUrl.
• Navigation timeout: a navigation that starts but never completes has its timeout error swallowed (logged, not thrown) and still resolves with a result; the URL stays unchanged so no navigatedToUrl is reported.
• Same-document hash navigation: skips the full navigation wait but is still surfaced via the before/after URL comparison.
• Action errors are rethrown to the caller.

Observation (current behavior, asserted as-is)

When a started navigation times out and remains pending, the subsequent stable-DOM wait cannot settle (in-page evaluations do not complete while the navigation is pending), so it consumes the full #stableDomTimeout. With {timeout: 500} the call still takes ~3.5s total (500ms navigation timeout + 3s stable-DOM timeout). The test documents this rather than changing it.

Note: this is independent of the open PR #2504 (popup tracking in WaitForHelper); it only touches network-multiplier and navigation/timeout behavior, so the two do not conflict.

Testing

• node scripts/test.js tests/WaitForHelper.test.ts — 11/11 pass (run 3x to check for flakes)
• npm run test:no-build — full suite green
• npm run check-format — clean

🤖 Generated with Claude Code

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