enhancement

[edouardmisset]

Parent issue: #13

What to build

End-to-end tracer bullet: create a working benchmark for one simple function (slugify), execute it with Deno.bench, and append one history record to benchmarks/history.jsonl with full metadata (git commit, Deno version, package version, date, hardware, stats).

Acceptance criteria

• Deno.bench harness for slugify exists at benchmarks/harness.ts
• Harness runs with fixed warmup=1s, time=2s
• One history record written to benchmarks/history.jsonl after execution
• Record includes: workspace, functionName, canonicalName, fixtureSize, gitCommit, denoVersion, benchmarkSchemaVersion, packageVersion, date, os, arch, cpuModel, skipped, stats (n, min, max, p75, p99, average)
• History file is append-only (does not overwrite existing records)
• Running the harness a second time adds a second record

Out of scope

• Auto-generation from exports
• Skip rules
• CLI task
• Regression detection