test(log): add comprehensive benchmarks

[taigrr]

Summary

Adds comprehensive benchmarks for the log-socket library to help measure performance and track regressions.

Fixes #6

Benchmarks Added

Serial Benchmarks (Single Log Levels)

• BenchmarkTrace, BenchmarkDebug, BenchmarkInfo
• BenchmarkNotice, BenchmarkWarn, BenchmarkError

Formatted Logging

• BenchmarkDebugf, BenchmarkInfof, BenchmarkErrorf

Parallel Benchmarks

• BenchmarkDebugParallel, BenchmarkInfoParallel, BenchmarkInfofParallel

Logger Instance (Namespaced Logging)

• BenchmarkLoggerInfo, BenchmarkLoggerInfof, BenchmarkLoggerDebugParallel

Multiple Clients/Namespaces

• BenchmarkMultipleClients - measures overhead with multiple consumers
• BenchmarkMultipleNamespaces - measures namespaced logging performance

Message Size Comparison

• BenchmarkInfoShortMessage - 2 chars
• BenchmarkInfoMediumMessage - ~60 chars
• BenchmarkInfoLongMessage - ~250 chars

Level Filtering Overhead

• BenchmarkDebugFilteredByLevel - measures overhead when logs are filtered

Sample Results (2 cores)

BenchmarkTrace-2                      56664       2556 ns/op
BenchmarkDebug-2                      48211       2351 ns/op
BenchmarkInfo-2                       41882       2573 ns/op
BenchmarkDebugf-2                     66877       2323 ns/op
BenchmarkInfoParallel-2               48004       2208 ns/op
BenchmarkLoggerInfo-2                 95398       1275 ns/op
BenchmarkLoggerDebugParallel-2       182540        619 ns/op
BenchmarkMultipleNamespaces-2        106291       1086 ns/op

Other Changes

• Moved duplicate BenchmarkDebugSerial from log_test.go to the new benchmark file
• Minor whitespace formatting fixes from goimports