Benchmark result struct

[codingwithmagga]

Description

Define a structured result type that captures all relevant metrics from a single benchmark run.

Acceptance Criteria

• Struct includes latency (min, max, mean), throughput, and hardware counter deltas
• Counter deltas are sourced from the profiling session (IPC, cache misses, branch mispredicts)
• Result is fully populated after a completed benchmark run
• Struct is serializable for use by output formatters

Notes

TDD — tests are written before implementation code.