fix: replace hrtime with performance not to allocate

[ferhatelmas]

What kind of change does this PR introduce?

refactor

What is the current behavior?

We use process.hrtime at the moment, which returns bigint. It's heap allocated.
It's not needed because a few seconds later, it's converted to a number for latency metrics.

What is the new behavior?

Use performance.now because it's monotonic, made for this purpose and not heap allocated.

Additional context

This cuts down garbage in hot paths.

[Copilot]

Pull request overview

This PR refactors latency measurements across the storage DB layer, queue scheduling, and HTTP metrics to use performance.now() (numeric monotonic timestamps) instead of process.hrtime.bigint(), reducing allocations in hot paths while preserving duration semantics (seconds).

Changes:

• Replace process.hrtime.bigint() start/end timing with performance.now() and compute durations in seconds via (now - start) / 1000.
• Update type surfaces where timing values are stored (e.g., FastifyRequest.metricsStartTime and DB duration recorder signature) from bigint to number.
• Add/adjust unit tests to assert metrics are recorded from numeric monotonic timestamps and to fix falsy-check behavior for 0 start times.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/storage/database/pg.ts	Switch DB query duration timing to performance.now() and update recorder signature to number.
src/storage/database/pg.test.ts	Add deterministic tests for scoped/unscoped DB query duration metrics using mocked performance.now().
src/internal/queue/event.ts	Switch queue scheduling timing to performance.now() and compute duration in seconds.
src/internal/queue/event.test.ts	Add test verifying queue scheduling duration metric uses numeric monotonic timestamps.
src/http/plugins/metrics.ts	Switch HTTP request timing to performance.now(), fix start-time presence check for 0, and update request augmentation type.
src/http/plugins/metrics.test.ts	Add test verifying HTTP metrics use numeric monotonic timestamps and that 0 is handled correctly.

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[coveralls]

Coverage Report for CI Build 28777683411

Coverage decreased (-0.008%) to 78.846%

Details

• Coverage decreased (-0.008%) from the base build.
• Patch coverage: 8 of 8 lines across 3 files are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	12239
Covered Lines:	10093
Line Coverage:	82.47%
Relevant Branches:	7039
Covered Branches:	5107
Branch Coverage:	72.55%
Branches in Coverage %:	Yes
Coverage Strength:	420.76 hits per line

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💛 - Coveralls