enhancement

[edouardmisset]

Depends on: #25

What to build

Add deno task bench command to deno.json that runs all generated benchmarks, collects results, and appends to history. Support optional --workspace=<name> filter for partial runs.

Acceptance criteria

• deno task bench defined in deno.json
• Task discovers all benchmarks/*.bench.ts files
• Task runs Deno.bench on all files and collects results
• Task appends results to benchmarks/history.jsonl
• deno task bench --workspace=array runs only array benchmarks
• deno task bench --workspace=date runs only date benchmarks
• History records include git commit, Deno version, schema version, package version, date, OS/arch, CPU model
• Task exits 0 on success

Out of scope

• Regression detection
• Baseline comparison