EPIC-07: Add CI perf regression and repro replay gates

[RtlZeroMemory]

Summary

• add reduced deterministic benchmark CI profile and runner (bench:ci)
• add threshold comparator with baseline config and actionable reports (bench:ci:compare)
• add committed CI baseline artifacts under benchmarks/ci-baseline/
• wire PR performance gate workflow with artifact upload
• add explicit replay-harness gate step on Linux CI for every PR
• add developer docs for perf regression workflow and repro replay CI usage

Validation

• npm run lint
• npm run typecheck
• npm run build
• npm test
• npm run test:e2e
• npm run test:e2e:reduced
• npm run test:native:smoke
• npm run bench:ci -- --output-dir /tmp/rezi-bench-ci-pr
• npm run bench:ci:compare -- --baseline benchmarks/ci-baseline/results.json --current /tmp/rezi-bench-ci-pr/results.json --config benchmarks/ci-baseline/config.json --report-json /tmp/rezi-bench-ci-pr/compare.json --report-md /tmp/rezi-bench-ci-pr/compare.md

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Regenerate perf baseline on CI runner environment

This baseline artifact was captured on a local WSL host (cpuModel is a desktop Ryzen and the file also records Node v20), but the perf gate in .github/workflows/ci.yml runs on ubuntu-latest with Node 22, so the comparator is gating absolute timing deltas against a different machine/runtime than the one used in CI. Because bench-ci-compare enforces hard thresholds on timing.mean, this can create persistent false regressions (or hide real ones) on every PR; the committed baseline should be generated in the same CI environment as the gate.

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