fix(observability): order TRA logs by request time + monotonic sequence (SDK-6164)

[harshit-browserstack]

SDK-6164 — TRA log timestamp ordering

Problem. Logs reach Test Observability but the Logs tab renders them out of order. The backend orders log events by their timestamp, and two emitters produced timestamps that didn't reflect emission order:

1. createHttpLogEvent stamped HTTP logs with the response-received time (httpResponse[0]). A slow request therefore sorted after logs that were emitted while it was still in flight.
2. No LogCreated event carried a tiebreaker, so logs sharing the same millisecond had a non-deterministic order.

Fix.

• Stamp HTTP logs with the request-issued time (httpRequest[0]). duration_ms is still measured request→response, so no metric regresses.
• Add a per-process monotonic sequence (new src/utils/logSequence.js) to every LogCreated event (TEST_LOG, HTTP, TEST_SCREENSHOT) so the backend can sort by (timestamp, sequence).

Verification. A standalone emission-boundary repro (stubbing helper.uploadEventData) shows the server-sorted (timestamp, sequence) order now equals emission order — inversion=false, tie=false. Added test/src/test-observability/logOrdering.js (4 cases) covering request-time stamping, post-sort ordering, same-ms tiebreaking, and the shared cross-kind sequence. All pass; eslint clean.

⚠️ Cross-team dependency: the sequence field is inert until the TRA backend adds it as a secondary sort key (timestamp, sequence). Fix #1 (request-time stamping) takes effect immediately since the backend already sorts by timestamp. The sequence tiebreaker needs the backend change to have any effect — tracked as a follow-up.

🤖 Generated with Claude Code

[harshit-browserstack]

Closing — this targeted the public upstream by mistake. Re-opening within the BrowserStack fork.