Record reproducible order-7 and order-8 measurements from the committed benchmark framework with a clean working tree. Include stable work counts, solve-time spread, validation and rendering cost, and interleaved instrumentation overhead.
Order 9 remains supported by the runner but retains its historical timing because each current run takes several minutes.
Benchmark: Apple arm64 Release, one warm-up, three repetitions
Refs: #8
Add an opt-in benchmark probe and JSON runner that separate solve, construction, validation, and rendering time. Record stable search counters, environment metadata, warm-up and repetition policy, timeouts, errors, median spread, and instrumentation overhead.
Compile production solving without counters and interleave counted and plain trials when measuring overhead. Keep heavyweight cases outside the default correctness path while testing counter and report behavior cheaply.
Tests: Debug and Release CTest suites (7 passed each)
Refs: #8