feat(logger): add benchmark script

[frytg]

What changed

Adds a standalone logger benchmark script that compares @frytg/logger against a plain Winston JSON logger.

• New logger/benchmark.ts script with warmup, stdout silencing during measurement, and ops/s reporting
• deno run bench-logger task and just bench-logger recipe
• Excludes benchmark.ts from JSR publish

Why

Closes #16. Provides a quick way to measure the overhead of the @frytg/logger wrapper (global context injection, error formatting) relative to raw Winston.

How to test

deno install --vendor
deno run check
deno run test
deno run bench-logger

Optional: pass a custom iteration count, e.g. deno run bench-logger 10000.

Sample output

Logger benchmark (50,000 iterations, runtime: deno-2.9.2)

winston (json)               328074 ops/s  (baseline)
@frytg/logger (json)         101797 ops/s  (31.0%)