Vouch Request: QQSHI13 — fix for #3292 (OTLP nanosecond timestamp overflow) #4927

Why do you want to contribute?

I'd like to fix issue #3292 (OTLP nanosecond timestamp overflow in the webapp event repository).

The bug: several places in the webapp multiply epoch milliseconds by 1_000_000 before converting to BigInt, which loses IEEE 754 precision (epoch-ns values are ~1.7e18, well past Number.MAX_SAFE_INTEGER), producing small errors in span timestamps. The affected functions are getNowInNanoseconds() and calculateDurationFromStart() in app/v3/eventRepository/common.server.ts, recordRunDebugLog() in app/v3/eventRepository/index.server.ts, and the retry event recording in app/v3/runEngineHandlers.server.ts.

I've already implemented the fix on a branch: all four sites now convert to BigInt before multiplying (BigInt(ms) * BigInt(1_000_000)), plus a colocated regression test (common.server.test.ts) that fails on the current code and passes with the fix — vitest shows 2 of 3 tests failing pre-fix (with a +64ns error at the exact-instant boundary) and 3/3 passing post-fix, and the webapp typecheck is clean. The branch is ready on my fork (QQSHI13/trigger.dev, branch fix/otlp-nanosecond-overflow) and I'll open the PR as soon as I'm vouched.

Prior contributions or relevant experience

TypeScript/Node.js work, including precision-sensitive data-pipeline code. Happy to iterate through review rounds.